Molten metal processing device, method, system and casting machine for forming metal products

Abstract

The present invention relates to an ultrasonic grain refinement and degassing process and system for metal casting, in particular, a molten metal processing device includes an assembly mounted on a casting wheel, including at least one vibration energy source that supplies vibration energy to molten metal cast in the casting wheel while the molten metal in the casting wheel is cooled, and a support device that holds the vibration energy source. An associated method for forming a metal product provides molten metal into a containment structure included as part of a casting machine, cools the molten metal in the containment structure, and couples vibration energy into the molten metal in the containment structure.

Description

[0001] This application is a divisional application of Chinese patent application No. 201680065872.3, filed on September 9, 2016, entitled “Ultrasonic Grain Refining and Degassing Procedure and System for Metal Casting”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application is related to U.S. Serial No. 62 / 372,592, filed on August 9, 2016, entitled ULTRASONIC GRAIN REFINING AND DEGASSING PROCEDURES AND SYSTEMS FOR METAL CASTING (the entire contents of which are incorporated herein by reference). This application is related to U.S. Serial No. 62 / 295,333, filed on February 15, 2016, entitled ULTRASONIC GRAIN REFINING AND DEGASSING FOR METAL CASTING (the entire contents of which are incorporated herein by reference). This application is related to U.S. Serial No. 62 / 267,507, filed on December 15, 2015, entitled ULTRASONIC GRAIN REFINING AND DEGASSING OF MOLTEN METAL (the entire contents of which are incorporated herein by reference). This application is related to U.S. Serial No. 62 / 113,882, filed on February 9, 2015, entitled ULTRASONIC GRAIN REFINING (the entire contents of which are incorporated herein by reference). This application is related to U.S. Serial No. 62 / 216,842, filed on September 10, 2015, entitled ULTRASONIC GRAIN REFINING ON ACONTINUOUS CASTING BELT (the entire contents of which are incorporated herein by reference). Technical Field

[0004] The present invention relates to a method for producing a metal casting having a controlled grain size, a system for producing a metal casting, and a product obtained from the metal casting. Background Art

[0005] Great efforts have been spent in the field of metallurgy to develop techniques for casting molten metal into continuous metal rods or cast products. Both batch casting and continuous casting have been well developed. Although both are mainly used in the industry, continuous casting has many advantages over batch casting.

[0006] In the continuous production of metal castings, molten metal passes from a holding furnace into a series of chutes and into the mold of a casting wheel where it is cast into a metal bar. The solidified metal bar is removed from the casting wheel and directed to a rolling mill where it is rolled into a continuous rod. Depending on the intended end use of the metal bar product and the alloy, the bar may undergo cooling during rolling, or the bar may be immediately cooled or quenched upon exiting the rolling mill to impart its desired mechanical and physical properties. Techniques such as those described in U.S. Pat. No. 3,395,560 to Cofer et al. (the entire contents of which are incorporated herein by reference) have been used to continuously process metal bar or bar products.

[0007] U.S. Pat. No. 3,938,991 to Sperry et al., the entire contents of which are incorporated herein by reference, illustrates the long-recognized problems that exist in the casting of "pure" metal products. This term "pure" metal casting refers to a metal or metal alloy formed from a primary metallic element designed for a particular conductivity or tensile strength or ductility, and does not include separate impurities added for grain control purposes.

[0008] Grain refinement is the process by which the crystal size of the newly formed phase is reduced by chemical or physical / mechanical means. Grain refiners are typically added to molten metals to significantly reduce the grain size of the solidifying structure during the solidification process or during the liquid to solid phase transformation process.

[0009] Indeed, WIPO patent application WO / 2003 / 033750 to Boily et al., the entire contents of which are incorporated herein by reference, describes the specific use of "grain refiners." The '750 application describes in its background section that in the aluminum industry, various grain refiners are generally incorporated into aluminum to form a master alloy. A typical master alloy used in aluminum casting includes from 1% to 10% titanium, and from 0.1% to 5% boron or carbon, with the remainder consisting essentially of aluminum or magnesium, with particles of TiB2 or TiC dispersed throughout the aluminum matrix. According to the '750 application, a master alloy containing titanium and boron can be produced by dissolving the desired amounts of titanium and boron in an aluminum melt. This is achieved by reacting molten aluminum with KBF4 and K2TiF6 at temperatures in excess of 800°C. These complex halide salts react very quickly with molten aluminum and provide titanium and boron to the melt.

[0010] The '750 application also describes that, as of 2002, this technology was used by nearly all grain refiner manufacturing companies to produce commercial master alloys. Grain refiners, often referred to as nucleating agents, are still in use today. For example, one commercial supplier of TIBOR master alloys states that close control of the casting structure is a major requirement for producing high quality aluminum alloy products.

[0011] Prior to the present invention, it was believed that grain refiners were the most effective way to provide a fine and uniform as-cast grain structure. The following reference (all of which is incorporated herein by reference) provides details of this background work: Abramov, OV, (1998), "High-Intensity Ultrasonics" Gordon and Breach Science Publishers (Amsterdam, The Netherlands) pp. 523 to 552.

[0012] Alcoa, (2000), "New Process for Grain Refinement of Aluminum", DOE Project Final Report, Contract No. DE-FC07-98ID13665, September 22, 2000.

[0013] Cui, Y., Xu, CL and Han, Q., (2007), "Microstructure Improvement in Weld Metal Using Ultrasonic Vibrations, Advanced Engineering Materials", Chapter 9, No. 3, pp. 161-163.

[0014] Eskin, GI, (1998), "Ultrasonic Treatment of Light Alloy Melts", Gordon and Breach Science Publishers (Amsterdam, The Netherlands).

[0015] Eskin, GI (2002) "Effect of Ultrasonic Cavitation Treatment of theMelt on the Microstructure Evolution during Solidification of Aluminum AlloyIngots", Zeitschrift Fur Metallkunde / Materials Research and AdvancedTechniques, Chapter 9, No. 6, June 2002, pp. 502 to 507.

[0016] Greer, A.L. (2004). "Grain Refinement of Aluminum Alloys". In Chu, M.G., Granger, D.A., & Han, Q. (Eds.), *Solidification of Aluminum Alloys*. Proceedings of a Symposium Sponsored by TMS (The Minerals, Metals & Materials Society), TMS (Warrendale, PA 15086 - 7528), pp. 131 - 145.

[0017] Han, Q. (2007). "The Use of Power Ultrasound for Material Processing". In Han, Q., Ludtka, G., & Zhai, Q. (Eds.), *Materials Processing under the Influence of External Fields*. Proceedings of a Symposium Sponsored by TMS (The Minerals, Metals & Materials Society), TMS (Warrendale, PA 15086 - 7528), pp. 97 - 106.

[0018] Jackson, K.A., Hunt, J.D., Uhlmann, D.R., & Seward, T.P. (1966). "On Origin of Equiaxed Zone in Castings". *Trans. Metall. Soc. AIME*, Vol. 236, pp. 149 - 158.

[0019] Jian, X., Xu, H., Meek, T.T., & Han, Q. (2005). "Effect of Power Ultrasound on Solidification of Aluminum A356 Alloy". *Materials Letters*, Vol. 59, No. 2 - 3, pp. 190 - 193.

[0020] Keles, O. and Dundar, M., (2007), "Aluminum Foil: Its Typical Quality Problems and Their Causes", Journal of Materials Processing Technology, Chapter 186, pp. 125-137.

[0021] Liu, C., Pan, Y. and Aoyama, S., (1998), Proceedings of the 5th International Conference on Semi-Solid Processing of Alloys and Composites, Eds.: Bhasin, AK, Moore, JJ, Young, KP and Madison, S., Colorado School of Mines (Golden, CO), pp. 439 to 447.

[0022] Megy, J., (1999), "Molten Metal Treatment", U.S. Patent No. 5,935,295, August 1999.

[0023] Megy, J., Granger, DA, Sigworth, GK and Durst, CR, (2000) "Effectiveness of In-Situ Aluminum Grain Refining Process", Light Metals, pp. 1 to 6.

[0024] Cui et al., "Microstructure Improvement in Weld Metal Using Ultrasonic Vibrations", Advanced Engineering Materials, 2007, Chapter 9, No. 3, pp. 161-163.

[0025] Han et al., “Grain Refining of Pure Aluminum,” Light Metals, 2012, pp. 967–971.

[0026] Prior to the present invention, U.S. Patent Nos. 8,574,336 and 8,652,397 (each of which is incorporated herein by reference in its entirety) described methods for reducing the amount of dissolved gases (and / or various impurities) in a molten metal bath, such as by introducing a purge gas into the molten metal bath near an ultrasonic device (e.g., ultrasonic degassing). These patents will hereinafter be referred to as the '336 patent and the '397 patent. Summary of the invention

[0027] In one embodiment of the present invention, a molten metal processing device for attachment to a casting wheel on a casting machine is provided. The device includes an assembly mounted on the casting wheel, including at least one vibration energy source that supplies vibration energy to the molten metal cast in the casting wheel while the molten metal in the casting wheel is cooling, and includes a support device that holds the vibration energy source.

[0028] In one embodiment of the invention, a method for forming a metal product is provided. The method provides molten metal to a containment structure included as part of a casting machine. The method cools the molten metal in the containment structure and couples vibration energy into the molten metal in the containment structure.

[0029] In one embodiment of the present invention, a system for forming a metal product is provided. The system comprises 1) a molten metal processing apparatus as described above, and 2) a controller comprising data inputs and control outputs and programmed with a control algorithm that allows operation of the above method steps.

[0030] In one embodiment of the present invention, a molten metal processing device is provided. The device includes a molten metal source, an ultrasonic degasser including an ultrasonic probe inserted into the molten metal, a casting mold for receiving the molten metal, an assembly mounted on the casting mold, including at least one vibration energy source for supplying vibration energy to the molten metal cast in the casting mold while cooling the molten metal in the casting mold, and a support device for holding at least one vibration energy source.

[0031] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary but not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A more complete appreciation of the present invention and many of its attendant advantages will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram of a continuous casting machine according to one embodiment of the present invention;

[0034] Figure 2A schematic diagram of a casting wheel configuration according to one embodiment of the present invention using at least one ultrasonic vibration energy source;

[0035] Figure 3 A schematic diagram of a casting wheel configuration according to one embodiment of the present invention, particularly using at least one mechanically driven vibration energy source;

[0036] Figure 3A is a schematic diagram of a casting wheel hybrid configuration according to one embodiment of the present invention using both at least one ultrasonic vibration energy source and at least one mechanically driven vibration energy source;

[0037] Figure 4 A schematic diagram of a casting wheel configuration according to one embodiment of the present invention showing a vibrating probe device directly coupled to molten metal cast in the casting wheel;

[0038] Figure 5 A schematic diagram of a fixed mold using the vibration energy source of the present invention;

[0039] FIG6A is a schematic cross-sectional view of selected components of a vertical casting machine;

[0040] FIG6B is a schematic cross-sectional view of other components of the vertical casting machine;

[0041] FIG6C is a schematic cross-sectional view of other components of the vertical casting machine;

[0042] FIG6D is a schematic cross-sectional view of other components of the vertical casting machine;

[0043] Figure 7 is a schematic diagram of an exemplary computer system for use with the controls and controllers depicted herein;

[0044] Figure 8 To draw a flow chart of a method according to one embodiment of the present invention;

[0045] Fig. 9 To illustrate a schematic diagram of an embodiment of the present invention using both ultrasonic degassing and ultrasonic grain refinement;

[0046] Fig.10 This is the process flow chart of ACSR line;

[0047] Fig.11 This is the process flow chart of ACSS line;

[0048] Fig.12 This is the process flow chart of aluminum strip;

[0049] Fig.13 A schematic side view of a casting wheel configuration according to one embodiment of the present invention using a magnetostrictive element for at least one ultrasonic vibration energy source;

[0050] Fig.14 for Fig.13 A schematic cross section of a magnetostrictive element;

[0051] Fig.15 Comparison of micrographs of aluminum 1350EC alloy showing the grain structure of castings without chemical grain refiners, with grain refiners, and with ultrasonic grain refinement only;

[0052] Fig.16 is a tabular comparison of conventional 1350EC aluminum alloy rod (with chemical grain refiner) and 1350EC aluminum alloy rod (with ultrasonic grain refinement);

[0053] Fig.17 A tabular comparison of conventional ACSR aluminum wire 0.130" diameter (with chemical grain refiner) and ACSR aluminum wire 0.130" diameter (with ultrasonic grain refinement);

[0054] Fig.18 A tabular comparison of conventional 8176EEE aluminum alloy rod (with chemical grain refiner) and 8176EEE aluminum alloy rod (with ultrasonic grain refinement);

[0055] Fig.19 A tabular comparison of conventional 5154 aluminum alloy rod (with chemical grain refiner) and 5154 aluminum alloy rod (with ultrasonic grain refinement);

[0056] Fig. 20 is a tabular comparison of conventional 5154 aluminum alloy strip (with chemical grain refiner) and 5154 aluminum alloy strip (with ultrasonic grain refinement); and

[0057] Fig.21 A tabular graph of the properties of 5356 aluminum alloy rod (with ultrasonic grain refinement). DETAILED DESCRIPTION

[0058] Grain refinement of metals and alloys is important for many reasons, including maximizing ingot casting rates, improving hot tearing resistance, minimizing element segregation, improving mechanical properties (particularly ductility), improving finishing characteristics of wrought products, and improving mold filling characteristics, as well as reducing porosity in cast alloys. Typically, grain refinement is one of the first processing steps used to produce metal and alloy products, especially aluminum and magnesium alloys, which are two of the increasingly used lightweight materials in the aerospace, defense, automotive, construction, and packaging industries. Grain refinement is also an important processing step for making metals and alloys that can be cast by eliminating columnar grains and forming equiaxed grains.

[0059] Grain refinement is a solidification process step by which the crystal size of the solid phase is reduced by chemical, physical or mechanical means in order to make the alloy castable and reduce defect formation. Currently, grain refinement is performed on aluminum production using TIBOR, resulting in the formation of an equiaxed grain structure in the solidified aluminum. Prior to the present invention, the use of impurities or chemical "grain refiners" was the only way to solve the problem of columnar grain formation in metal castings that has always been recognized in the metal casting industry. In addition, prior to the present invention, the combination of 1) ultrasonic degassing to remove impurities from the molten metal (before casting) and 2) the above-mentioned ultrasonic grain refinement (i.e., at least one vibration energy source) was not performed. However, due to the input of those inoculants into the melt, the costs associated with the use of TIBOR and mechanical limitations are high. Some of the limitations include ductility, machinability and conductivity.

[0060] Regardless of cost, approximately 68% of aluminum produced in the United States is first cast into ingots before further processing into sheets, plates, extrusions or foils. The direct chill (DC) semi-continuous casting process and the continuous casting (CC) process have become mainstays in the aluminum industry primarily due to their robust nature and relative simplicity. One problem with the DC and CC processes is the formation of hot tears or cracks during ingot solidification. Essentially, almost all ingots will crack (or be uncastable) without the use of grain refinement.

[0061] Nevertheless, the productivity of these modern processes is limited by the conditions under which cracks are avoided. Grain refinement is an effective way to reduce the alloy's tendency to hot tear and thus increase productivity. As a result, a great deal of effort has been focused on developing stronger grain refiners that can produce the smallest possible grain size. If the grain size can be reduced to submicron levels, superplasticity can be achieved, which allows the alloy to be not only cast at faster rates, but also rolled / extruded at lower temperatures at faster rates than ingots processed today, resulting in significant cost and energy savings.

[0062] At present, almost all the aluminum cast in the world, either from primary (about 20 billion kg) or secondary and internal scrap (25 billion kg), is grain refined with heterogeneous cores of insoluble TiB2 nuclei of about a few microns in diameter, which nucleate into a fine grain structure in the aluminum. One problem with the use of chemical grain refiners is the limited grain refining capacity. In fact, the use of chemical grain refiners causes a limited reduction in the aluminum grain size from a columnar structure with linear grain sizes of some exceeding 2,500 μm to equiaxed grains of less than 200 μm. Equiaxed grains of 100 μm in aluminum alloys represent the limit of what can be obtained using commercially available chemical grain refiners.

[0063] If the grain size can be further reduced, productivity can be significantly improved. Grain size at the submicron level leads to superplasticity that makes aluminum alloys easier to form at room temperature.

[0064] Another problem with the use of chemical grain refiners is the defect formation associated with the use of grain refiners. Although considered necessary for grain refinement in the prior art, insoluble foreign particles are otherwise undesirable in aluminum, particularly in the form of particle aggregates ("clusters"). Current grain refiners in the form of compounds in aluminum-based master alloys are manufactured by a complex series of mining, beneficiation and manufacturing processes. Currently used master alloys typically contain potassium aluminum fluoride (KAIF) salts and aluminum oxide impurities (dross), which emerge from the conventional manufacturing process of aluminum grain refiners. This causes local defects in aluminum (e.g., "leaks" in beverage cans and "pinholes" in thin foils), machine tool wear, and surface finishing problems in aluminum. Data from one of the aluminum wire companies indicates that 25% of production defects are attributed to TiB2 particle aggregates, while another 25% of defects are attributed to dross trapped in the aluminum during the casting process. TiB2 particle aggregates often break the wire during extrusion, especially when the diameter of the wire is less than 8 mm.

[0065] Another issue regarding the use of chemical grain refiners is the cost of the grain refiner. This is particularly true for the production of magnesium ingots using Zr grain refiners. The grain refinement cost of using Zr grain refiners is approximately $1 per kg of magnesium produced by casting. The grain refiner cost for aluminum alloys is approximately $1.50 per kg.

[0066] Another problem with the use of chemical grain refiners is reduced electrical conductivity. The use of chemical grain refiners causes excess Ti in the aluminum, causing a large reduction in the electrical conductivity of pure aluminum used for wire applications. In order to maintain a certain conductivity, companies must pay extra money to use purer aluminum to make wires and filaments.

[0067] Many other grain refining methods besides chemical methods have been developed over the past century. These methods include the use of physical fields, such as magnetic and electromagnetic fields, and the use of mechanical vibrations. High-intensity, low-amplitude ultrasonic vibrations are one of the physical / mechanical mechanisms that have been demonstrated to be used for grain refining of metals and alloys without the use of foreign particles. However, experimental results such as those from Cui et al. in 2007, as mentioned above, were obtained in small ingots of up to a few pounds of metal subjected to ultrasonic vibrations for a short period of time. The use of high-intensity ultrasonic vibrations has little effect on the grain refining of CC or DC ingots / billets.

[0068] Some of the technical challenges addressed in the present invention for grain refining are (1) coupling ultrasonic energy to the molten metal for extended periods of time, (2) maintaining the natural vibration frequency of the system at elevated temperatures, and (3) increasing the grain refining efficiency of ultrasonic grain refining when the temperature of the ultrasonic waveguide is hot. Enhanced cooling for both the ultrasonic waveguide and the ingot (as described below) is one of the approaches proposed herein to address these challenges.

[0069] Furthermore, another technical challenge addressed in the present invention relates to the fact that the purer the aluminum, the harder the equiaxed grains obtained during the solidification process. Even with the use of external grain refiners such as TiB (titanium boride) in pure aluminum such as 1000, 1100 and 1300 series aluminum, it is still difficult to obtain an equiaxed grain structure. However, using the novel grain refinement technique described herein, significant grain refinement has been achieved.

[0070] In one embodiment of the invention, the invention partially suppresses columnar grain formation without the need to introduce grain refiners. Applying vibration energy to the molten metal as it is poured into the mold allows for achieving grain sizes comparable to or smaller than those obtained using prior art grain refiners such as TIBOR master alloys.

[0071] As used herein, embodiments of the present invention will use the terms commonly used by those skilled in the art to describe their work. These terms should conform to the common meaning understood by those of ordinary skill in the field of materials science, metallurgy, metal casting and metal processing. Some terms with more professional meanings are described in the following embodiments. However, the term "configured to" is understood herein to describe an appropriate structure (shown herein or known or implied from the art), thereby allowing its target to perform the function of following the "configured to" term. The term "coupled to" means that an object coupled to a second object has a required structure to support a first object (e.g., abut, attach, displace a predetermined distance from it, adjacent, continuous, linked together, separated from each other, disassembled from each other, fixed together, in sliding contact, in rolling contact) in a position about the second object, with or without the direct attachment of the first and second objects together.

[0072] U.S. Patent No. 4,066,475 to Chia et al., the entire contents of which are incorporated herein by reference, describes a continuous casting process. In general, Figure 1A continuous casting system is depicted having a casting machine 2 including a pouring spout 11 that directs molten metal to a peripheral groove contained on a rotating mold ring 13. An endless flexible metal belt 14 surrounds both a portion of the mold ring 13 and a portion of a set of belt positioning rollers 15 so that a continuous casting mold is defined by the groove in the mold ring 13 and the overlying metal belt 14. A cooling system is provided for cooling the apparatus and achieving controlled solidification of the molten metal during its transport on the rotating mold ring 13. The cooling system includes a plurality of side headers 17, 18 and 19 disposed on the sides of the mold ring 13, and inner and outer belt headers 20 and 21 disposed on the inner and outer sides of the metal belt 14, respectively, at locations where it surrounds the mold ring. A network of conduits 24 with suitable valves is connected to supply and discharge coolant to the various headers in order to control cooling of the apparatus and the solidification rate of the molten metal.

[0073] So configured, molten metal is fed from the pouring spout 11 into the casting mold and solidifies and partially cools during its transport by the circulation of a coolant through the cooling system. A solid cast bar 25 is taken from the casting wheel and fed to a conveyor 27 which conveys the cast bar to a rolling mill 28. It should be noted that the cast bar 25 is cooled only an amount sufficient to solidify the bar, and the bar is maintained at an elevated temperature to allow an immediate rolling operation to be performed thereon. The rolling mill 28 may include a tandem array of rolling stands which continuously roll the bar into a continuous length of wire rod 30 having a generally uniform circular cross-section.

[0074] Figure 1 and 2 A controller 500 is shown that, as described in more detail below, controls various portions of the continuous casting system described herein. The controller 500 may include one or more processors with programmed instructions (ie, algorithms) to control the operation of the continuous casting system and its components.

[0075] In one embodiment of the present invention, Figure 2 As shown in FIG. 1 , the casting machine 2 includes a casting wheel 30 having a containment structure 32 (e.g., a groove or channel in the casting wheel 30) into which molten metal is poured (e.g., cast), and a molten metal processing device 34. A belt 36 (e.g., a steel flexible metal belt) confines the molten metal in the containment structure 32 (i.e., the channel). Rollers 38 allow the molten metal processing device 34 to remain in a stationary position on the rotating casting wheel as the molten metal solidifies in the channel of the casting wheel and is transferred away from the molten metal processing device 34.

[0076] In one embodiment of the present invention, the molten metal processing device 34 includes an assembly 42 mounted on the casting wheel 30. The assembly 42 includes at least one vibration energy source (e.g., vibrator 40), a housing 44 (i.e., a support device) that holds the vibration energy source 42. The assembly 42 includes at least one cooling channel 46 for conveying a cooling medium therethrough. The flexible belt 36 is sealed to the housing 44 by a seal 44a attached to the underside of the housing, thereby allowing the cooling medium to flow from the cooling channel along the side of the flexible belt opposite the molten metal in the channel of the casting wheel. An air wipe 52 directs air (as a safety precaution) so that any water leaking from the cooling channel will be directed in a direction away from the casting source of the molten metal. The seal 44a can be made of many materials, including ethylene propylene, fluororubber, nitrile rubber (nitrile), neoprene, silicone rubber, urethane, fluorosilicone, polytetrafluoroethylene, and other known sealant materials. In one embodiment of the present invention, a guide device (e.g., roller 38) guides the molten metal processing device 34 relative to the rotating casting wheel 30. The cooling medium provides cooling to the molten metal in the containment structure 32 and / or at least one vibrational energy source 40. In one embodiment of the present invention, the components of the molten metal processing device 34 including the housing may be made of metals such as titanium, stainless steel alloys, mild steel or H13 steel, other high temperature materials, ceramics, composites, or polymers. The components of the molten metal processing device 34 may be made of one or more of niobium, niobium alloys, titanium, titanium alloys, tantalum, tantalum alloys, copper, copper alloys, rhenium, rhenium alloys, steel, molybdenum, molybdenum alloys, stainless steel, and ceramics. The ceramic may be a silicon nitride ceramic, such as, for example, silicon oxide aluminum nitride or SIALON.

[0077] In one embodiment of the invention, as the molten metal passes under the metal strip 36 under the vibrator 40, vibration energy is supplied to the molten metal as the metal begins to cool and solidify. In one embodiment of the invention, the vibration energy is imparted by an ultrasonic transducer, such as generated by a piezoelectric device ultrasonic transducer. In one embodiment of the invention, the vibration energy is imparted by an ultrasonic transducer, such as generated by a magnetostrictive transducer. In one embodiment of the invention, the vibration energy is imparted by a mechanically driven vibrator (discussed later). In one embodiment, the vibration energy allows the formation of a plurality of small seeds, thereby producing a fine grained metal product.

[0078] In one embodiment of the invention, ultrasonic grain refinement involves applying ultrasonic energy (and / or other vibrational energy) to refine grain size. Although the invention is not limited to any particular theory, one theory is that injecting vibrational energy (e.g., ultrasonic energy) into a molten or solidifying alloy can induce nonlinear effects such as cavitation, acoustic streaming, and radiation pressure. These nonlinear effects can be used to nucleate new grains and break up dendrites during the solidification process of the alloy.

[0079] Under this theory, the grain refinement process can be divided into two stages: 1) nucleation, and 2) growth of the newly formed solid from the liquid. Spherical nuclei are formed during the nucleation stage. These nuclei develop into dendrites during the growth stage. The unidirectional growth of dendrites leads to the formation of columnar grains, which may cause hot tearing / cracks and non-uniform distribution of secondary phases. This in turn can lead to poor castability. On the other hand, uniform growth of dendrites in all directions (as is possible in the present invention) leads to the formation of equiaxed grains. Castings / ingots containing small and equiaxed grains have excellent formability.

[0080] Under this theory, nucleation can occur when the temperature in the alloy is below the liquidus temperature and when the size of the solid crystal is larger than the critical size given by the following equation:

[0081]

[0082] where r* is the critical size, σ sl is the interfacial energy associated with the solid-liquid interface, and ΔG V is the Gibbs free energy associated with converting a unit volume of liquid into a solid.

[0083] Under this theory, the Gibbs free energy ΔTG V When its size is larger than r*, it decreases with the increase of the size of the solid crystal blank, indicating that the growth of the solid crystal blank is thermodynamically favorable. In this case, the solid crystal blank becomes a stable nucleus. However, homogeneous nucleation of a solid phase with a size larger than r* only occurs under extreme conditions requiring large undercooling in the melt.

[0084] Under this theory, nuclei formed during solidification can grow into solid grains known as dendrites. Dendrites can also be broken into multiple small fragments by applying vibrational energy. The dendrite fragments formed can grow into new grains and lead to the formation of small grains; thus creating an equiaxed grain structure.

[0085] While not limited to any particular theory, a relatively small amount of undercooling (e.g., less than 2, 5, 10, or 15° C.) of the molten metal at the top of the channel of the casting wheel 30 (e.g., against the underside of the belt 36) causes a layer of small nuclei of pure aluminum (or other metal or alloy) to form against the steel belt. Vibrational energy (e.g., ultrasonic or mechanically driven vibrations) releases these nuclei, which then act as nucleating agents during solidification, resulting in a uniform grain structure. Thus, in one embodiment of the present invention, the cooling method used ensures that the small amount of undercooling at the top of the channel of the casting wheel 30 against the steel belt results in small nuclei of material that is processed into the molten metal as the molten metal continues to cool. The vibrations acting on the belt 36 serve to disperse these nuclei into the molten metal in the channel of the casting wheel 30, and / or may be used to break up dendrites that form in the undercooled layer. For example, the vibrational energy imparted to the molten metal as it cools can break up dendrites to form new nuclei by cavitation (see below). These nuclei and fragments of dendrites can then be used to form (promote) equiaxed grains in the mold during solidification, resulting in a uniform grain structure.

[0086] In other words, ultrasonic vibrations delivered to the supercooled liquid metal create nucleation sites in the metal or metal alloy to refine the grain size. The nucleation sites can be generated via the vibrational energy of breaking up dendrites generated in the molten metal as described above, without relying on multiple nuclei of foreign impurities. In one aspect, the channel of the casting wheel 30 can be a refractory metal or other high temperature material, such as copper, iron and steel, niobium, niobium and molybdenum, tantalum, tungsten, and rhenium, and alloys thereof, including one or more elements such as silicon, oxygen, or nitrogen that can extend the melting point of these materials.

[0087] In one embodiment of the present invention, the ultrasonic vibration source used for the vibration energy source 40 provides a power of 1.5 kW at an acoustic frequency of 20 kHz. The present invention is not limited to those powers and frequencies. Instead, a wide range of powers and ultrasonic frequencies can be used, although the following ranges are of interest.

[0088] power : Generally, depending on the size of the ultrasonic generator or probe, for each ultrasonic generator, the power is between 50 and 5000 W. These powers are usually applied to the ultrasonic generator to ensure that the power density at the end of the ultrasonic generator is higher than 100 W / cm 2 , which, depending on the cooling rate of the molten metal, the type of molten metal, and other factors, may be considered a threshold for inducing cavitation in the molten metal. The power at this region may range from 50 to 5000 W, 100 to 3000 W, 500 to 2000 W, 1000 to 1500 W, or any intermediate or overlapping ranges. Higher powers for larger probes / ultrasonic generators and lower powers for smaller probes are possible: in various embodiments of the present invention, the applied vibration energy power density may range from 10 W / cm 2 Up to 500W / cm2 , or 20W / cm 2 Up to 400W / cm 2 , or 30W / cm 2 Up to 300W / cm 2 , or 50W / cm 2 Up to 200W / cm 2 , or 70W / cm 2 Up to 150W / cm 2 , or any intermediate or overlapping ranges thereof.

[0089] frequency : Generally, 5 to 400 kHz (or any intermediate range) can be used. Alternatively, 10 and 30 kHz (or any intermediate range) can be used. Alternatively, 15 and 25 kHz (or any intermediate range) can be used. The applied frequency can range from 5 to 400 kHz, 10 to 30 kHz, 15 to 25 kHz, 10 to 200 kHz, or 50 to 100 kHz, or any intermediate or overlapping ranges thereof.

[0090] In one embodiment of the present invention, at least one vibrator 40 is provided to be coupled to the cooling channel 46, which vibrator 40 provides ultrasonic vibration energy into the liquid metal via the cooling medium and via the assembly 42 and the belt 36 in the case of an ultrasonic probe of an ultrasonic transducer (or an ultrasonic generator, a piezoelectric transducer or an ultrasonic transmitter or a magnetostrictive element). In one embodiment of the present invention, the ultrasonic energy is supplied from a transducer capable of converting electric current into mechanical energy, thereby generating a vibration frequency higher than 20 kHz (e.g., up to 400 kHz), wherein the ultrasonic energy is supplied from one or both of the piezoelectric element or the magnetostrictive element.

[0091] In one embodiment of the invention, an ultrasonic probe is inserted into the cooling channel 46 to contact the liquid cooling medium. In one embodiment of the invention, the separation distance (if any) from the tip of the ultrasonic probe to the belt 36 is variable. The separation distance may be, for example, less than 1 mm, less than 2 mm, less than 5 mm, less than 1 cm, less than 2 cm, less than 5 cm, less than 10 cm, less than 20 cm, or less than 50 cm. In one embodiment of the invention, more than one ultrasonic probe or an array of ultrasonic probes may be inserted into the cooling channel 46 to contact the liquid cooling medium. In one embodiment of the invention, the ultrasonic probe may be attached to the wall of the assembly 42.

[0092] In one aspect of the present invention, a piezoelectric transducer that supplies vibration energy may be formed of a ceramic material sandwiched between electrodes that provide attachment points for electrical contact. Once a voltage is applied to the ceramic via the electrodes, the ceramic expands and contracts at ultrasonic frequencies. In one embodiment of the present invention, a piezoelectric transducer used as a vibration energy source 40 is attached to an enhancer that transmits vibration to the probe. U.S. Patent No. 9,061,928 (the entire contents of which are incorporated herein by reference) describes an ultrasonic transducer assembly including an ultrasonic transducer, an ultrasonic enhancer, an ultrasonic probe, and an enhancer cooling unit. The ultrasonic enhancer in the '928 patent is connected to the ultrasonic transducer to amplify the acoustic energy generated by the ultrasonic transducer and transmit the amplified acoustic energy to the ultrasonic probe. The enhancer construction of the '928 patent can be used in the present invention to provide energy to an ultrasonic probe that is in direct or indirect contact with the liquid cooling medium discussed above.

[0093] In fact, in one embodiment of the present invention, an ultrasonic enhancer is used in the field of ultrasound to amplify or enhance the vibration energy generated by a piezoelectric transducer. The enhancer does not increase or decrease the frequency of the vibration, it increases the amplitude of the vibration. (When the enhancer is mounted in reverse, it also compresses the vibration energy). In one embodiment of the present invention, the enhancer is connected between the piezoelectric transducer and the probe. In the case of using the enhancer for ultrasonic grain refinement, the following is an exemplary number of method steps showing the use of the enhancer with a piezoelectric vibration energy source:

[0094] 1) Electric current is supplied to the piezoelectric transducer. Once the current is applied, the ceramic inside the transducer expands and contracts, which converts the current into mechanical energy.

[0095] 2) In one embodiment, those vibrations are then transmitted to a booster, which amplifies or strengthens the mechanical vibrations.

[0096] 3) In one embodiment, the amplified or enhanced vibrations from the intensifier are then propagated to the probe. The probe then vibrates at ultrasonic frequencies, thus creating cavitation.

[0097] 4) Cavitation from the vibrating probe affects the casting strip, which in one embodiment is in contact with the molten metal.

[0098] 5) In one embodiment, cavitation breaks up dendrites and produces an equiaxed grain structure.

[0099] See also Figure 2 The probe is coupled to a cooling medium flowing through the molten metal processing device 34. The cavitation created in the cooling medium by the vibration of the probe at ultrasonic frequencies affects the strip 36 in contact with the molten aluminum in the containment structure 32.

[0100] In one embodiment of the present invention, the vibration energy may be supplied by a magnetostrictive transducer used as the vibration energy source 40. In one embodiment, the magnetostrictive transducer used as the vibration energy source 40 has a Figure 2 The same arrangement is used for the piezoelectric transducer unit in, wherein the only difference is that the ultrasonic source driving the surface to vibrate at ultrasonic frequencies is at least one magnetostrictive transducer instead of at least one piezoelectric element. Fig.13 A casting wheel configuration according to one embodiment of the present invention using a magnetostrictive element for at least one ultrasonic vibration energy source is depicted. In this embodiment of the present invention, the magnetostrictive transducer(s) 40a vibrate a probe coupled to a cooling medium (at a frequency of, for example, 30 kHz) Fig.13 4 (not shown in the side view of FIG. 4 ), although other frequencies may be used as described below. In another embodiment of the present invention, the magnetostrictive transducer 40a vibrates the molten metal processing device 34. Fig.14 The bottom plate 40b shown in the schematic cross-sectional view of FIG. 1 , wherein the bottom plate 40b is connected to the cooling medium ( Fig.14 ).

[0101] Magnetostrictive transducers are typically made of a large number of material plates that expand and contract once an electromagnetic field is applied. More specifically, in one embodiment, a magnetostrictive transducer suitable for the present invention may include a large number of nickel (or other magnetostrictive material) plates or stacks arranged parallel to one edge of each stack attached to the bottom of a processing container or other surface to be vibrated. A coil is placed around the magnetostrictive material to provide a magnetic field. For example, when a current is supplied through the coil, a magnetic field is generated. The magnetic field causes the magnetostrictive material to contract or elongate, thereby introducing sound waves into the fluid in contact with the expanding and contracting magnetostrictive material. Typical ultrasonic frequencies from magnetostrictive transducers suitable for the present invention range from 20kHz to 200kHz. Higher or lower frequencies may be used depending on the natural frequency of the magnetostrictive element.

[0102] Nickel is one of the most commonly used materials for magnetostrictive transducers. When voltage is applied to the transducer, the nickel material expands and contracts at ultrasonic frequencies. In one embodiment of the present invention, the nickel plate is silver brazed directly to the stainless steel plate. Figure 2 , the stainless steel plate of the magnetostrictive transducer is the surface that vibrates at ultrasonic frequencies and is directly coupled to the surface (or probe) of the cooling medium flowing through the molten metal processing device 34. The cavitation created in the cooling medium via the plate vibrating at ultrasonic frequencies then affects the belt 36 that is in contact with the molten aluminum in the containment structure 32.

[0103] U.S. Patent No. 7,462,960 (the entire contents of which are incorporated herein by reference) describes an ultrasonic transducer driver having a giant magnetostrictive element. Thus, in one embodiment of the present invention, the magnetostrictive element may be made of a rare earth alloy-based material, such as Terfenol-D and its composites, which have an unusually large magnetostrictive effect compared to early transition metals such as iron (Fe), cobalt (Co), and nickel (Ni). Alternatively, in one embodiment of the present invention, the magnetostrictive element may be made of iron (Fe), cobalt (Co), and nickel (Ni).

[0104] Alternatively, in one embodiment of the present invention, the magnetostrictive element may be made of one or more of the following alloys: iron and terbium; iron and praseodymium; iron, terbium and praseodymium; iron and dysprosium; iron, terbium and dysprosium; iron, praseodymium and dysprosium; iron, terbium, praseodymium and dysprosium; iron and erbium; iron and samarium; iron, erbium and samarium; iron, samarium and dysprosium; iron and holmium; iron, samarium and holmium; or mixtures thereof.

[0105] U.S. Patent No. 4,158,368 (the entire contents of which are incorporated herein by reference) describes a magnetostrictive transducer. As described herein and applicable to the present invention, a magnetostrictive transducer may include a plunger of a material exhibiting negative magnetostriction disposed within a housing. U.S. Patent No. 5,588,466 (the entire contents of which are incorporated herein by reference) describes a magnetostrictive transducer. As described herein and applicable to the present invention, a magnetostrictive layer is applied to a flexible element, such as a flexible beam. The flexible element is deflected by an external magnetic field. As shown in the '466 patent and applicable to the present invention, a thin magnetostrictive layer can be used for a magnetostrictive element composed of Tb(1-x)Dy(x)Fe2. U.S. Patent No. 4,599,591 (the entire contents of which are incorporated herein by reference) describes a magnetostrictive transducer. As described herein and applicable to the present invention, a magnetostrictive transducer may use a magnetostrictive material and a plurality of windings connected to a plurality of current sources having a phase relationship so as to form a rotating magnetic induction vector within the magnetostrictive material. U.S. Patent No. 4,986,808 (the entire contents of which are incorporated herein by reference) describes a magnetostrictive transducer. As described herein and applicable to the present invention, the magnetostrictive transducer may include a plurality of elongated strips of magnetostrictive material, each strip having a proximal end, a distal end, and a generally V-shaped cross-section, wherein each arm of the V is formed by the longitudinal length of the strip, and each strip is attached to an adjacent strip at both the proximal and distal ends to form and integrally bond a generally rigid column having a central axis with fins extending radially about the axis.

[0106] Figure 3A schematic diagram of another embodiment of the present invention showing a mechanical vibration configuration for supplying low frequency vibration energy to the molten metal in the channel of the casting wheel 30. In one embodiment of the present invention, the vibration energy comes from mechanical vibrations generated by a transducer or other mechanical agitator. As known in the art, a vibrator is a mechanical device that generates vibrations. Vibrations are typically generated by an electric motor with an unbalanced mass on its drive shaft. Some mechanical vibrators consist of an electromagnetic drive and an agitator shaft that stirs by vertical reciprocating motion. In one embodiment of the present invention, the vibration energy is supplied from a vibrator (or other member) that is capable of using mechanical energy to generate a vibration frequency of up to, but not limited to, 20 kHz, and preferably in the range of 5-10 kHz.

[0107] Regardless of the vibration mechanism, attaching a vibrator (a piezoelectric transducer, a magnetostrictive transducer, or a mechanically driven vibrator) to the housing 44 means that vibrational energy can be transferred to the molten metal in the channel below the assembly 42 .

[0108] The mechanical vibrator used in the present invention can vibrate 8,000 to 15,000 times per minute, although higher and lower frequencies can be used. In one embodiment of the present invention, the vibration mechanism is configured to vibrate between 565 and 5,000 vibrations per second. In one embodiment of the present invention, the vibration mechanism is configured to vibrate at a frequency of a fraction of a vibration per second to 565 vibrations per second or even lower. The range of mechanically driven vibrations suitable for the present invention includes, for example, 6,000 to 9,000 vibrations per minute, 8,000 to 10,000 vibrations per minute, 10,000 to 12,000 vibrations per minute, 12,000 to 15,000 vibrations per minute, and 15,000 to 25,000 vibrations per minute. The range of mechanically driven vibrations suitable for the present invention reported in the literature includes, for example, the range from 133 to 250 Hz, 200 Hz to 283 Hz (12,000 to 17,000 vibrations per minute) and 4 to 250 Hz. Additionally, a wide variety of mechanically driven oscillations may be imparted into the casting wheel 30 or housing 44 by a simple hammer or plunger arrangement that is periodically driven to strike the casting wheel 30 or housing 44. In general, mechanical vibrations may range up to 10 kHz. Thus, ranges of mechanical vibrations suitable for use in the present invention include: 1 to 10 KHz, 10 Hz to 4000 Hz, 20 Hz to 2000 Hz, 40 Hz to 1000 Hz, 100 Hz to 500 Hz, and intermediate and combined ranges thereof, including a preferred range of 565 to 5,000 Hz.

[0109] Although described above with reference to ultrasonic and mechanically driven embodiments, the present invention is not so limited to one or the other of these ranges, but can be used for a wider spectrum of vibration energy up to 400KHz, including single frequency and multi-frequency sources. In addition, a combination of sources (ultrasonic and mechanically driven sources or different ultrasonic sources, or different mechanically driven sources and acoustic energy sources, as described below) can be used.

[0110] like Figure 3 As shown in FIG. 1 , the casting machine 2 includes a casting wheel 30 having a containment structure 32 (e.g., a trough or channel) in the casting wheel 30 into which the molten metal is poured, and a molten metal processing device 34. A belt 36 (e.g., a steel belt) confines the molten metal in the containment structure 32 (i.e., the channel). As described above, the rollers 38 allow the molten metal processing device 34 to remain stationary while the molten metal 1) solidifies in the channel of the casting wheel and 2) is transferred away from the molten metal processing device 34.

[0111] The cooling channels 46 convey a cooling medium therethrough. As previously described, the air knives 52 direct the air (as a safety precaution) so that any water leaking from the cooling channels is directed in a direction away from the casting source of the molten metal. As previously described, the rolling devices (e.g., rollers 38) direct the molten metal processing device 34 relative to the rotating casting wheel 30. The cooling medium is directed toward the molten metal and the at least one vibration energy source 40 ( Figure 3 Shown is a mechanical vibrator 40) providing cooling.

[0112] As the molten metal passes under the metal strip 36 below the mechanical vibrator 40, mechanically driven vibrational energy is supplied to the molten metal as it begins to cool and solidify. In one embodiment, the mechanically driven vibrational energy allows for the formation of a plurality of small seeds, thereby producing a fine grained metal product.

[0113] In one embodiment of the invention, at least one vibrator 40 is provided coupled to the cooling channel 46, which in the case of a mechanical vibrator provides mechanically driven vibration energy into the liquid metal via the cooling medium, and via the assembly 42 and the band 36. In one embodiment of the invention, the head of the mechanical vibrator is inserted into the cooling channel 46 to contact the liquid cooling medium. In one embodiment of the invention, more than one mechanical vibrator head or an array of mechanical vibrator heads may be inserted into the cooling channel 46 to contact the liquid cooling medium. In one embodiment of the invention, the mechanical vibrator head may be attached to the wall of the assembly 42.

[0114] While not limited to any particular theory, a relatively small amount of undercooling (e.g., less than 10°C) at the bottom of the channel of the casting wheel 30 results in the formation of a small nucleus layer of purer aluminum (or other metal or alloy). Mechanically driven vibrations create these nuclei, which then act as nucleating agents during solidification, resulting in a uniform grain structure. Therefore, in one embodiment of the present invention, the cooling method used ensures a small amount of undercooling at the bottom of the channel, resulting in a small nucleus layer of the processed material. The mechanically driven vibrations from the bottom of the channel disperse these nuclei and / or can be used to break up dendrites formed in the undercooled layer. Fragments of these nuclei and dendrites are then used to form equiaxed grains in the mold during solidification, resulting in a uniform grain structure.

[0115] In other words, in one embodiment of the present invention, mechanically driven vibrations transmitted to the liquid metal create nucleation sites in the metal or metal alloy to refine the grain size. As described above, the channels of the casting wheel 30 can be refractory metals or other high temperature materials, such as copper, iron and steel, niobium, niobium and molybdenum, tantalum, tungsten, and rhenium, and alloys thereof, including one or more elements such as silicon, oxygen, or nitrogen that can extend the melting point of these materials.

[0116] Figure 3A Schematic diagram of a casting wheel hybrid configuration according to one embodiment of the present invention using both at least one ultrasonic vibration energy source and at least one mechanically driven vibration energy source (e.g., a mechanically driven vibrator). Figure 3 Those elements shown together in the are similar elements that perform similar functions as described above. For example, Figure 3A The receiving structure 32 (groove or channel) mentioned in the drawing is in the casting wheel into which the molten metal is poured. As above, the belt ( Figure 3A 32) to confine the molten metal to the containment structure 32. Here, in this embodiment of the invention, both the (multiple) ultrasonic vibration energy source and the (multiple) mechanically driven vibration energy source can be selectively activated and can be driven separately or in conjunction with each other to provide vibrations that, when delivered to the liquid metal, create nucleation sites in the metal or metal alloy to refine the grain size. In various embodiments of the invention, different combinations of (multiple) ultrasonic vibration energy sources and (multiple) mechanically driven vibration energy sources can be arranged and used.

[0117] Invention

[0118] In one aspect of the invention, vibrational energy (from a low frequency mechanically driven vibrator in the range of 8,000 to 15,000 vibrations per minute or up to 10 KHz and / or ultrasonic frequencies in the range of 5 to 400 kHz) can be applied to the molten metal containment structure during cooling. In one aspect of the invention, the vibrational energy can be applied at a plurality of different frequencies. In one aspect of the invention, the vibrational energy can be applied to a variety of metal alloys, including but not limited to those metals and alloys listed below: aluminum, copper, gold, iron, nickel, platinum, silver, zinc, magnesium, titanium, niobium, tungsten, manganese, iron and alloys and combinations thereof; metal alloys include - brass (copper / zinc), bronze (copper / tin), steel (iron / carbon), chromium alloys (chromium), stainless steel (steel / chromium), tool steel (carbon / tungsten / manganese), titanium (iron / aluminum) and standard grades of aluminum alloys, including - 1100, 1350, 2024, 222 4,5052,5154,5356.5183, 6101,6201,6061,6053,7050,7075,8XXX series; copper alloys, including bronze (described above) and alloys of copper in combination with zinc, tin, aluminum, silicon, nickel, silver; magnesium alloys with aluminum, zinc, manganese, silicon, copper, nickel, zirconium, beryllium, calcium, cerium, neodymium, strontium, tin, yttrium, rare earths; iron and iron alloys with chromium, carbon, silicon chromium, nickel, potassium, plutonium, zinc, zirconium, titanium, lead, magnesium, tin, scandium; and other alloys and combinations thereof.

[0119] In one aspect of the invention, vibration energy (from a low frequency mechanically driven vibrator, in the range of 8,000 to 15,000 vibrations per minute or up to 10 KHz and / or ultrasonic frequencies in the range of 5 to 400 kHz) is coupled to the solidifying metal under the molten metal processing device 34 via a liquid medium in contact with the belt. In one aspect of the invention, the vibration energy is mechanically coupled between 565 and 5,000 Hz. In one aspect of the invention, the vibration energy is mechanically driven at even lower frequencies as low as a fraction of a vibration per second to 565 vibrations per second. In one aspect of the invention, the vibration energy is ultrasonically driven at frequencies ranging from 5 kHz to 400 kHz. In one aspect of the invention, the vibration energy is coupled via a housing 44 that houses the vibration energy source 40. The housing 44 is connected to other structural elements such as the belt 46 or rollers 38, which are in contact with the walls of the channel or directly with the molten metal. In one aspect of the invention, this mechanical coupling transmits the vibration energy from the vibration energy source to the molten metal as the metal cools.

[0120] In one aspect, the cooling medium can be a liquid medium such as water. In one aspect, the cooling medium can be a gaseous medium, such as one of compressed air or nitrogen. In one aspect, the cooling medium can be a phase change material. Preferably, the cooling medium is provided at a sufficient rate to supercool the metal near the band 36 (less than 5 to 10° C. above the liquidus temperature of the alloy or even below the liquidus temperature).

[0121] In one aspect of the invention, equiaxed grains within the cast product are obtained without the need to add impure particles such as titanium boride to the metal or metal alloy to increase the grain count and improve uniform heterogeneous solidification.Instead of using nucleating agents, in one aspect of the invention, vibrational energy can be used to create nucleation sites.

[0122] During operation, molten metal at a temperature substantially above the liquidus temperature of the alloy flows by gravity into the channel of the casting wheel 30 and passes under the molten metal handling device 34 where it is exposed to vibration energy (i.e., ultrasonic or mechanically driven vibration). The temperature of the molten metal flowing into the channel of the mold depends on the type of alloy selected, the pouring rate, the size of the casting wheel channel, and other factors. For aluminum alloys, the casting temperature can range from 1220F to 1350F, with preferred ranges, for example, between 1220 to 1300F, 1220 to 1280F, 1220 to 1270F, 1220 to 1340F, 1240 to 1320F, 1250 to 1300F, 1260 to 1310F, 1270 to 1320F, 1320 to 1330F, with overlaps and intermediate ranges and variations of ±10 degrees Fahrenheit also being suitable. The channels of the casting wheel 30 are cooled to ensure that the molten metal in the channels is close to the sub-liquidus temperature (e.g., less than 5 to 10°C above the liquidus temperature of the alloy or even below the liquidus temperature, although the pouring temperature may be much higher than 10°C). During operation, the atmosphere around the molten metal may be controlled by a shroud (not shown) that is, for example, filled or poured with an inert gas such as Ar, He or nitrogen. The molten metal on the casting wheel 30 is generally in a thermally stable state where the molten metal is transformed from a liquid to a solid.

[0123] Due to undercooling near the subliquidus temperature, the solidification rate is not slow enough to allow equilibrium across the solid-liquid interface, which in turn results in variations in composition across the cast bar. Inhomogeneities in chemical composition lead to segregation. Furthermore, the amount of segregation is directly related to the diffusion coefficients of the various elements in the molten metal and the rate of heat transfer. Another type of segregation is where the component with the lower melting point will solidify first.

[0124] In an ultrasonic or mechanically driven vibration embodiment of the present invention, the vibration energy stirs the molten metal as it cools. In this embodiment, the vibration energy is imparted with energy that stirs and effectively stirs the molten metal. In one embodiment of the present invention, the mechanically driven vibration energy is used to continuously stir the molten metal as it cools. In various casting alloy processes, it is desirable to contain high concentrations of silicon in aluminum alloys. However, at higher silicon concentrations, silicon precipitates may form. By "remixing" these precipitates back into the molten state, elemental silicon may be at least partially returned to the solution. Alternatively, even if the precipitate is left behind, the mixing will not result in segregation of the silicon precipitate, thereby causing greater abrasive wear on downstream metal molds and rollers.

[0125] In various metal alloy systems, some type of effect occurs where one component of the alloy (usually the higher melting point component) precipitates in pure form, in effect "contaminating" the alloy with particles of the pure component. Generally, when an alloy is cast, segregation occurs whereby the concentration of the solute is not constant throughout the casting. This can be caused by a variety of processes. Microsegregation, which occurs over distances comparable to the size of the dendrite arm gaps, is thought to be the result of the first solid to form having a concentration lower than the final equilibrium concentration, causing excess solute to separate into the liquid so that subsequently formed solids have a higher concentration. Macrosegregation occurs over distances similar to the size of the casting. This can be caused by a number of complex processes involving shrinkage effects as the casting solidifies, and changes in liquid density as the solute separates. It is desirable to prevent segregation during casting to give a solid billet that has uniform properties throughout.

[0126] Thus, some alloys that would benefit from the vibrational energy treatment of the present invention include those mentioned above.

[0127] Other structures

[0128] The present invention is not limited to the application of vibrational energy to only the channel structures described above. In general, vibrational energy (from a low frequency mechanically driven vibrator, in the range of up to 10 KHz and / or ultrasonic frequencies in the range of 5 to 400 kHz) can include nucleation at a point in the casting process where the molten metal begins to cool from a molten state and enter a solid state (i.e., a thermally stable state). Viewed differently, in various embodiments, the present invention combines vibrational energy from a variety of sources with thermal management so that the molten metal near the cooling surface approaches the liquidus temperature of the alloy. In these embodiments, the temperature of the molten metal in the channel or relative to the band 36 of the casting wheel 30 is low enough to induce nucleation and crystal growth (dendrite formation), while the vibrational energy creates nuclei and / or breaks up dendrites that may form on the surface of the channel in the casting wheel 30.

[0129] In one embodiment of the invention, the advantages associated with the casting process can be obtained without an energized or continuously energized vibration energy source. In one embodiment of the invention, the vibration energy source can be energized during a programmed on / off cycle with a percentage range of amplitude with respect to the duty cycle from 0 to 100%, 10-50%, 50-90%, 40-60%, 45-55%, and all intermediate ranges therebetween by controlling the power to the vibration energy source.

[0130] In another embodiment of the present invention, vibration energy (ultrasonic or mechanically driven) is injected directly into the molten aluminum mold in the casting wheel before the belt 36 contacts the molten metal. The direct application of vibration energy causes alternating pressure in the melt. Ultrasonic energy applied directly to the molten metal as vibration energy can cause cavitation in the molten melt.

[0131] Although not bound by any particular theory, cavitation consists of the formation of tiny discontinuities or cavities in a liquid, which then grow, pulsate, and collapse. Cavities appear due to tensile stresses generated by sound waves in the rarefaction phase. If the tensile stress (or negative pressure) persists after the cavity is formed, the cavity will expand to several times its initial size. During cavitation in an ultrasonic field, many cavities appear simultaneously at a distance less than the ultrasonic wave length. In this case, the cavity bubbles retain their spherical shape. The subsequent behavior of the cavitation bubbles is highly variable: a small portion of the bubbles coalesce to form large bubbles, but almost all of them collapse by the sound waves in the compression phase. During compression, some of these cavities may collapse due to compressive stresses. Therefore, high shock waves appear in the melt when these cavities collapse. Therefore, in one embodiment of the present invention, the shock waves caused by the vibration energy are used to break up dendrites and other growing nuclei, thereby generating new nuclei, which in turn leads to an equiaxed grain structure. In addition, in another embodiment of the present invention, continuous ultrasonic vibrations can effectively homogenize the formed nuclei, further contributing to the equiaxed structure. In another embodiment of the present invention, discontinuous ultrasonic or mechanically driven vibrations may effectively homogenize the formed nuclei, further contributing to the equiaxed structure.

[0132] Figure 4 Schematic diagram of a casting wheel configuration according to one embodiment of the present invention, particularly in conjunction with a vibrating probe device 66 having a probe (not shown) inserted directly into the molten metal cast in the casting wheel 60. The probe will have a configuration similar to that used for ultrasonic degassing as is known in the art. Figure 4Rollers 62 are depicted pressing a belt 68 onto the edge of the casting wheel 60. A vibrating probe device 66 couples vibration energy (ultrasonic or mechanically driven energy) directly or indirectly into the molten metal being cast in the channel (not shown) of the casting wheel 60. As the casting wheel 60 rotates counterclockwise, the molten metal is transformed under the rollers 62 and comes into contact with an optional molten metal cooling device 64. This device 64 may be similar to Figure 2 and 3 The device 64 may be similar to the component 42 of FIG. Figure 3 The molten metal processing device 34 is provided in the embodiment of the present invention, but without the mechanical vibrator 40.

[0133] In this embodiment, if Figure 4 As shown in , the molten metal processing device for a casting machine uses at least one vibration energy source (i.e., a vibration probe device 66) that supplies vibration energy through a probe inserted into the molten metal cast in the casting wheel (preferably but not necessarily directly into the molten metal cast in the casting wheel) while the molten metal in the casting wheel is cooled. A support device holds the vibration energy source (vibration probe device 66) in place.

[0134] In another embodiment of the present invention, vibration energy can be coupled into the molten metal while it is cooled by air or gas as a medium by using an acoustic oscillator. An acoustic oscillator (e.g., an audio amplifier) ​​can be used to generate and transmit sound waves into the molten metal. In this embodiment, the ultrasonic or mechanically driven vibrator discussed above will be replaced or supplemented by an acoustic oscillator. An audio amplifier suitable for the present invention will provide acoustic oscillations from 1 to 20,000 Hz. Acoustic oscillations above or below this range can be used. For example, acoustic oscillations from 0.5 to 20 Hz; 10 to 500 Hz, 200 to 2,000 Hz, 1,000 to 5,000 Hz, 2,000 to 10,000 Hz, 5,000 to 14,000 Hz, and 10,000 to 16,000 Hz, 14,000 to 20,000 Hz, and 18,000 to 25,000 Hz can be used. An electroacoustic transducer can be used to generate and transmit acoustic energy.

[0135] In one embodiment of the invention, acoustic energy may be coupled directly into the molten metal via a gaseous medium, where the acoustic energy vibrates the molten metal. In one embodiment of the invention, acoustic energy may be coupled directly into the molten metal via a gaseous medium, where the acoustic energy vibrates the belt 36 or other support structure containing the molten metal, which in turn vibrates the molten metal.

[0136] In addition to using the vibration energy treatment of the present invention in the continuous wheel casting system described above, the present invention also has application in stationary molds and vertical casting machines.

[0137] For stationary machines, the molten metal is poured into a stationary cast 62, such as Figure 5 , which itself has a molten metal processing device 34 (schematically shown). In this way, vibration energy (from a low frequency mechanically driven vibrator, up to 10KHz operation and / or ultrasonic frequencies in the range of 5 to 400kHz) can cause nucleation at the point in the fixed mold where the molten metal begins to cool from the molten state and enter the solid state (i.e., thermally stable state).

[0138] Figures 6A-6D Selected components of a vertical casting machine are depicted. Further details of these components and other aspects of a vertical casting machine are found in U.S. Patent No. 3,520,352 (the entire contents of which are incorporated herein by reference). Figures 6A-6D As shown in FIG. 1 , the vertical casting machine includes a molten metal casting cavity 213, which is generally square in the illustrated embodiment, but which may be circular, elliptical, polygonal or any other suitable shape, and which is defined by vertical intersecting first wall portions 215 and second or corner wall portions 217, located in the top of the mold. A fluid retaining enclosure 219 surrounds the walls 215 and the corner members 217 of the casting cavity in spaced relation thereto. The enclosure 219 is adapted to receive a cooling fluid, such as water, via an inlet conduit 221 and to discharge the cooling fluid via an outlet conduit 223.

[0139] While the first wall portion 215 is preferably made of a very thermally conductive material such as copper, the second or corner wall portion 217 is constructed of a less thermally conductive material such as, for example, a ceramic material. Figures 6A-6D As shown in , the corner wall portion 217 has a generally L-shaped or angled cross-section, with the vertical edges of each corner inclined downwardly and converging toward each other. Thus, the corner member 217 terminates at some convenient level in the mold above the discharge end of the mold between the transverse sections.

[0140] In operation, molten metal flows from a tundish (sometimes also called a tundish) 245 into a casting mold, which reciprocates vertically, and a cast strand of metal is continuously taken from the mold. The molten metal first cools in the mold as it contacts the cooler mold walls, which can be considered the first cooling zone. Heat is rapidly removed from the molten metal in this zone, and a skin of material is believed to be fully formed around the central pool of molten metal.

[0141] In one embodiment of the invention, a vibrational energy source (a vibrator 40 shown schematically only on FIG. 6D for simplicity) will be disposed about the fluid retaining enclosure 219, and preferably into the cooling medium circulating in the fluid retaining enclosure 219. The vibrational energy (from a low frequency mechanically driven vibrator, in the range of 8,000 to 15,000 times per minute and / or an ultrasonic frequency in the range of 5 to 400 kHz, and / or an acoustic oscillator as described above) will cause nucleation at the point in the casting process where the molten metal begins to cool from the molten state and enters the solid state (i.e., thermally stable state) as the molten metal transitions from liquid to solid and as a cast strand of metal is continuously withdrawn from the metal casting cavity 213.

[0142] In one embodiment of the present invention, the ultrasonic grain refinement described above is combined with the ultrasonic degassing described above to remove impurities from the molten bath prior to metal casting. Fig. 9 To illustrate one embodiment of the invention using both ultrasonic degassing and ultrasonic grain refinement. As described herein, a furnace is a source of molten metal. The molten metal is delivered from the furnace in a launder. In one embodiment of the invention, an ultrasonic degasser is provided in the path of the launder before the molten metal is provided to a casting machine (e.g., a casting wheel) containing an ultrasonic grain refiner (not shown). In one embodiment, the grain refiner in the casting machine need not occur at ultrasonic frequencies, but may occur at one or more of the other mechanically driven frequencies discussed elsewhere.

[0143] Although not limited to the following particular ultrasonic degasser, the '336 patent describes degassers suitable for use in various embodiments of the present invention. One suitable degasser would be an ultrasonic device having an ultrasonic transducer; an elongated probe including a first end and a second end, the first end being attached to the ultrasonic transducer and the second end including a tip; and a purge gas delivery system, wherein the purge gas delivery system may include a purge gas inlet and a purge gas outlet. In some embodiments, the purge gas outlet may be within approximately 10 cm (or 5 cm, or 1 cm) of the tip of the elongated probe, while in other embodiments, the purge gas outlet may be at the tip of the elongated probe. In addition, the ultrasonic device may include multiple probe assemblies and / or multiple probes per ultrasonic transducer.

[0144] Although not limited to the specific ultrasonic degasser below, the '397 patent describes degassers suitable for use with various embodiments of the present invention. One suitable degasser would be an ultrasonic device having an ultrasonic transducer; a probe attached to the ultrasonic transducer, the probe including a tip; and a gas delivery system, the gas delivery system including a gas inlet, a gas flow path through the probe, and a gas outlet at the tip of the probe. In one embodiment, the probe may be an elongated probe including a first end and a second end, the first end being attached to the ultrasonic transducer and the second end including the tip. In addition, the probe may include stainless steel, titanium, niobium, ceramic, and the like, or a combination of any of these materials. In another embodiment, the ultrasonic probe may be a single SIALON probe with an integrally integrated gas delivery system therethrough. In yet another embodiment, the ultrasonic device may include multiple probe assemblies and / or multiple probes for each ultrasonic transducer.

[0145] In one embodiment of the invention, ultrasonic degassing, for example using the ultrasonic probe discussed above, supplements ultrasonic grain refinement. In various embodiments of ultrasonic degassing, a purge gas is added to the molten metal, for example, through the probe discussed above, at a rate in the range of from about 1 to about 50 L / min. By way of disclosure, the flow rate is in the range of from about 1 to about 50 L / min. The flow rate may be about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, about 25, about 26, about 27, about 28, about 29, about 30, about 31, about 32, about 33, about 34, about 35, about 36, about 37, about 38, about 39, about 40, about 41, about 42, about 43, about 44, about 45, about 46, about 47, about 48, about 49, or about 50 L / min. In addition, the flow rate can be in any range from about 1 to about 50 L / min (e.g., the rate can be in the range of about 2 to about 20 L / min), and this also includes any combination of ranges between about 1 and about 50 L / min. Intermediate ranges are possible. Likewise, all other ranges disclosed herein should be understood in a similar manner.

[0146] Embodiments of the present invention relate to ultrasonic degassing, and ultrasonic grain refinement can provide systems, methods and / or apparatus for ultrasonic degassing of molten metals, including but not limited to aluminum, copper, steel, zinc, magnesium and the like, or combinations of these and other metals (e.g., alloys). Processing or casting products from molten metals may require a bath containing the molten metal, which bath of the molten metal may be maintained at an elevated temperature. For example, molten copper may be maintained at a temperature of approximately 1100°C, while molten aluminum may be maintained at a temperature of approximately 750°C.

[0147] As used herein, the terms "bath," "molten metal bath," and the like are meant to encompass any container that may contain molten metal, including vessels, crucibles, troughs, troughs, furnaces, ladles, etc. The bath and molten metal bath terms are used to encompass operations that are batch, continuous, semi-continuous, etc., and, for example, where the molten metal is substantially stationary (e.g., as typically associated with a crucible) and where the molten metal is substantially moving (e.g., as typically associated with a launder).

[0148] Many instruments or devices are available for monitoring, testing or changing the state of the molten metal in the bath, and for the final production or casting of the desired metal product. These instruments or devices are needed to better withstand the elevated temperatures encountered in the molten metal bath, advantageously have a longer life and are limited to not react with the molten metal, whether the metal is (or the metal includes) aluminum, or copper, or steel, or zinc, or magnesium, etc.

[0149] In addition, the molten metal may have one or more gases dissolved in them, and these gases may adversely affect the final production and casting of the desired metal product, and / or the resulting material properties of the metal product itself. For example, the gas dissolved in the molten metal may include hydrogen, oxygen, nitrogen, sulfur dioxide and the like, or a combination thereof. In some cases, it may be advantageous to remove the gas or reduce the amount of gas in the molten metal. As an example, dissolved hydrogen may be detrimental to the casting of aluminum (or copper, or other metals or alloys), and therefore, the properties of the final product produced by aluminum (or copper, or other metals or alloys) can be improved by reducing the amount of hydrogen carried in the molten bath of aluminum (or copper, or other metals or alloys). Dissolved hydrogen based on mass higher than 0.2ppm, higher than 0.3ppm, or higher than 0.5ppm may have an adverse effect on the casting rate and the quality of the resulting aluminum (or copper, or other metals or alloys) rods and other products. Hydrogen may enter the molten aluminum (or copper, or other metal or alloy) either through its presence in the atmosphere above the bath containing the molten aluminum (or copper, or other metal or alloy), or it may be present in the aluminum (or copper, or other metal or alloy) feed starting material used in the molten aluminum (or copper, or other metal or alloy) bath.

[0150] Attempts to reduce the amount of dissolved gas in a molten metal bath have not been completely successful. Typically, these processes in the past involve additional and expensive equipment, as well as potentially dangerous materials. For example, a process used in the metal casting industry to reduce the dissolved gas content of a molten metal may consist of a rotor made of a material such as graphite, and these rotors may be placed in a molten metal bath. In addition, chlorine may be added to the molten metal bath at a location near the rotor in the molten metal bath. Although the addition of chlorine can successfully reduce the amount of dissolved hydrogen in a molten metal bath in some cases, for example, this conventional process has noticeable drawbacks, the most important of which are cost, complexity, and the use of chlorine, which may be dangerous and may be harmful to the environment.

[0151] In addition, the molten metals may have impurities present in them, and these impurities may adversely affect the final production and casting of the desired metal product, and / or the resulting physical properties of the metal product itself. For example, impurities in the molten metal may include alkali metals or other metals that are not required or expected to be present in the molten metal. Small percentages of certain metals are present in various metal alloys, and this metal will not be considered an impurity. As a non-limiting example, impurities may include lithium, sodium, potassium, lead and the like, or a combination thereof. Various impurities may enter the molten metal bath (aluminum, copper or other metals or alloys) by their presence in the incoming metal feed starting material used in the molten metal bath.

[0152] Embodiments of the present invention related to ultrasonic degassing and ultrasonic grain refinement can provide a method for reducing the amount of dissolved gas in a molten metal bath, or in other words, a method for degassing a molten metal. One such method may include operating an ultrasonic device in a molten metal bath, and introducing a purge gas into the molten metal bath adjacent to the ultrasonic device. The dissolved gas may be or may include oxygen, hydrogen, sulfur dioxide, and the like, or a combination thereof. For example, the dissolved gas may be or may include hydrogen. The molten metal bath may include aluminum, copper, zinc, steel, magnesium, and the like, or a mixture and / or combination thereof (e.g., various alloys including aluminum, copper, zinc, steel, magnesium, etc.). In some embodiments related to ultrasonic degassing and ultrasonic grain refinement, the molten metal bath may include aluminum, while in other embodiments, the molten metal bath may include copper. Therefore, the molten metal in the bath may be aluminum, or alternatively, the molten metal may be copper.

[0153] In addition, embodiments of the present invention may provide methods for reducing the amount of impurities present in a molten metal bath, or in other words, methods for removing impurities. One such method involving ultrasonic degassing and ultrasonic grain refinement may include operating an ultrasonic device in a molten metal bath, and introducing a purge gas into the molten metal bath adjacent to the ultrasonic device. Impurities may be or may include lithium, sodium, potassium, lead, and the like, or a combination thereof. For example, impurities may be or may include lithium or, alternatively, sodium. The molten metal bath may include aluminum, copper, zinc, steel, magnesium, and the like, or a mixture and / or combination thereof (e.g., various alloys including aluminum, copper, zinc, steel, magnesium, etc.). In some embodiments, the molten metal bath may include aluminum, while in other embodiments, the molten metal bath may include copper. Therefore, the molten metal in the bath may be aluminum, or, alternatively, the molten metal may be copper.

[0154] The purging gas disclosed herein involving ultrasonic degassing and ultrasonic grain refinement used in the degassing method and / or impurity removal method may include one or more of nitrogen, helium, neon, argon, krypton and / or xenon, but is not limited thereto. It is conceivable that any suitable gas can be used as a purging gas, provided that the gas does not significantly react with or dissolve in the (multiple) characteristic metals in the molten metal bath. In addition, a mixture or combination of gases can be used. According to some embodiments disclosed herein, the purging gas may be or may include an inert gas; alternatively, the purging gas may be or may include a rare gas; alternatively, the purging gas may be or may include helium, neon, argon, or a combination thereof; alternatively, the purging gas may be or may include helium; alternatively, the purging gas may be or may include neon; or alternatively, the purging gas may be or may include argon. In addition, the applicant conceives that in some embodiments, conventional degassing techniques may be used in conjunction with the ultrasonic degassing process disclosed herein. Thus, in some embodiments, the purge gas may further include chlorine, such as chlorine used alone as a purge gas or in combination with at least one of nitrogen, helium, neon, argon, krypton, and / or xenon.

[0155] However, in some embodiments of the present invention, methods involving ultrasonic degassing and ultrasonic grain refinement for degassing or for reducing the amount of dissolved gas in a molten metal bath may be performed in the substantial absence or absence of chlorine. As used herein, substantial absence means that no more than 5% by weight of chlorine may be used based on the amount of purge gas used. In some embodiments, the methods disclosed herein may include the introduction of a purge gas, and the purge gas may be selected from the group consisting of nitrogen, helium, neon, argon, krypton, xenon, and combinations thereof.

[0156] The amount of purge gas introduced into the molten metal bath may vary depending on many factors. Typically, the amount of purge gas introduced into the method for degassing the molten metal (and / or the method for removing impurities from the molten metal) according to an embodiment of the present invention for ultrasonic degassing and ultrasonic grain refinement may fall within the range of about 0.1 to about 150 standard liters per minute (L / min). In some embodiments, the amount of purge gas introduced may be in the range of from about 0.5 to about 100 L / min, from about 1 to about 100 L / min, from about 1 to about 50 L / min, from about 1 to about 35 L / min, from about 1 to about 25 L / min, from about 1 to about 10 L / min, from about 1.5 to about 20 L / min, from about 2 to about 15 L / min, or from about 2 to about 10 L / min. These volume flow rates are in standard liters per minute, i.e., at standard temperature (21.1 ° C) and pressure (101 kPa).

[0157] In a continuous or semi-continuous molten metal operation, the amount of purge gas introduced into the molten metal bath may vary based on the molten metal output or production rate. Therefore, the amount of purge gas introduced in the method for degassing molten metal (and / or the method for removing impurities from molten metal) according to this embodiment involving ultrasonic degassing and ultrasonic grain refinement may fall within the range of about 10 to about 500 mL / hr of purge gas per kg / hr of molten metal (mL purge gas / kg molten metal). In some embodiments, the ratio of the volume flow rate of the purge gas to the output rate of the molten metal may be in the range of from about 10 to about 400 mL / kg; alternatively, from about 15 to about 300 mL / kg; alternatively, from about 20 to about 250 mL / kg; alternatively, from about 30 to about 200 mL / kg; alternatively, from about 40 to about 150 mL / kg; or alternatively, from about 50 to about 125 mL / kg. As mentioned above, the volume flow rate of the purge gas is at standard temperature (21.1°C) and pressure (101 KPa).

[0158] The method for degassing molten metal according to an embodiment of the present invention and involving ultrasonic degassing and ultrasonic grain refinement can effectively remove more than about 10 weight percent of the dissolved gas present in the molten metal bath, that is, the amount of dissolved gas in the molten metal bath can be reduced by about 10 weight percent from the amount of dissolved gas present before the degassing process is used. In some embodiments, the amount of dissolved gas present can be reduced by more than about 15 weight percent, more than about 20 weight percent, more than about 25 weight percent, more than about 35 weight percent, more than about 50 weight percent, more than about 75 weight percent, or more than about 80 weight percent from the amount of dissolved gas present before the degassing method is used. For example, if the dissolved gas is hydrogen, a hydrogen level in a molten metal bath containing aluminum or copper greater than about 0.3ppm or 0.4ppm or 0.5ppm (based on mass) may be unfavorable, and the hydrogen content in the molten metal may be about 0.4ppm, about 0.5ppm, about 0.6ppm, about 0.7ppm, about 0.8ppm, about 0.9ppm, about 1ppm, about 1.5ppm, about 2ppm or more than 2ppm. It is contemplated that the amount of dissolved gas in a molten metal bath can be reduced to less than about 0.4 ppm using the methods disclosed in embodiments of the present invention; alternatively, to less than about 0.3 ppm; alternatively, to less than about 0.2 ppm; alternatively, in a range from about 0.1 to about 0.4 ppm; alternatively, in a range from about 0.1 to about 0.3 ppm; or alternatively, in a range from about 0.2 to about 0.3 ppm. In these and other embodiments, the dissolved gas can be or can include hydrogen, and the molten metal bath can be or can include aluminum and / or copper.

[0159] Embodiments of the invention relating to ultrasonic degassing and ultrasonic grain refinement and directed to methods of degassing (e.g., reducing the amount of dissolved gas in a bath comprising molten metal) or methods of removing impurities may include operating an ultrasonic device in a molten metal bath. The ultrasonic device may include an ultrasonic transducer and an elongated probe, and the probe may include a first end and a second end. The first end may be attached to the ultrasonic transducer, and the second end may include a tip, and the tip of the elongated probe may include niobium. Details of exemplary and non-limiting examples of ultrasonic devices that may be used in the processes and methods disclosed herein are described below.

[0160] Since it belongs to the ultrasonic degassing process or the process for removing impurities, the purge gas can be introduced into the molten metal bath, for example, at a position near the ultrasonic device. In one embodiment, the purge gas can be introduced into the molten metal bath at a position near the tip of the ultrasonic device. In one embodiment, the purge gas can be introduced into the molten metal bath within about 1 meter of the tip of the ultrasonic device, for example, within about 100 cm, within about 50 cm, within about 40 cm, within about 30 cm, within about 25 cm, or within about 20 cm of the tip of the ultrasonic device. In some embodiments, the purge gas can be introduced into the molten metal bath within about 15 cm of the tip of the ultrasonic device; alternatively, within about 10 cm; alternatively, within about 8 cm; alternatively, within about 5 cm; alternatively, within about 3 cm; alternatively, within about 2 cm; or alternatively, within about 1 cm. In a specific embodiment, the purge gas can be introduced into the molten metal bath near the tip of the ultrasonic device or through it.

[0161] Although not intended to be bound by this theory, the use of ultrasonic devices and the combination of adjacent purge gas lead to a dramatic reduction in the amount of dissolved gas in the bath containing molten metal. The ultrasonic energy generated by the ultrasonic device can generate cavitation bubbles in the melt, into which the dissolved gas can diffuse. However, without the purge gas, many cavitation bubbles can collapse before reaching the surface of the molten metal bath. The purge gas can reduce the amount of cavitation bubbles that collapse before reaching the surface, and / or can increase the size of the bubbles containing dissolved gas, and / or can increase the number of bubbles in the molten metal bath, and / or can increase the rate at which the bubbles containing dissolved gas are transported to the surface of the molten metal bath. The ultrasonic device can generate cavitation bubbles in the vicinity of the tip of the ultrasonic device. For example, for an ultrasonic device with a tip of about 2 to 5 cm in diameter, the cavitation bubbles can be within about 15 cm, about 10 cm, about 5 cm, about 2 cm, or about 1 cm of the tip of the ultrasonic device before collapse. If the purge gas is added at a distance too far from the tip of the ultrasonic device, the purge gas may not diffuse into the cavitation bubbles. Therefore, in embodiments involving ultrasonic degassing and ultrasonic grain refinement, the purge gas is introduced into the molten metal bath within about 25 cm to about 20 cm of the tip of the ultrasonic device, and more advantageously, within about 15 cm, within about 10 cm, within about 5 cm, within about 2 cm, or within about 1 cm of the tip of the ultrasonic device.

[0162] Ultrasonic devices according to embodiments of the present invention may be in contact with molten metals such as aluminum or copper, for example, as disclosed in U.S. Patent Publication No. 2009 / 0224443, which is incorporated herein by reference in its entirety. In an ultrasonic device for reducing the dissolved gas content (e.g., hydrogen) in a molten metal, niobium or its alloys may be used as a protective barrier for the device when it is exposed to the molten metal, or as a component of the device that is directly exposed to the molten metal.

[0163] Embodiments of the present invention involving ultrasonic degassing and ultrasonic grain refinement may provide systems and methods for extending the life of components in direct contact with molten metal. For example, embodiments of the present invention may use niobium to reduce the degradation of materials in contact with molten metal, resulting in significant quality improvements in the final product. In other words, embodiments of the present invention may extend the life of or protect materials or components in contact with molten metal by using niobium as a protective barrier. Niobium may have properties such as its high melting point, which may help provide the aforementioned embodiments of the present invention. In addition, niobium may also form a protective oxide barrier when exposed to temperatures of about 200°C and higher.

[0164] In addition, embodiments of the present invention involving ultrasonic degassing and ultrasonic grain refinement can provide systems and methods for extending the life of components that are in direct contact or interface with molten metals. Since niobium has a lower reactivity with certain molten metals, the use of niobium can prevent degradation of the base material. Therefore, embodiments of the present invention involving ultrasonic degassing and ultrasonic grain refinement can use niobium to reduce the degassing of the base material, resulting in significant quality improvements in the final product. Therefore, niobium associated with molten metal can combine the high melting point of niobium and its low reactivity with molten metals such as aluminum and / or copper.

[0165] In some embodiments, niobium or its alloys can be used in an ultrasonic device including an ultrasonic transducer or an elongated probe. The elongated probe may include a first end and a second end, wherein the first end may be attached to the ultrasonic transducer and the second end may include a tip. According to the present invention, the tip of the elongated probe may include niobium (e.g., niobium or its alloys). As discussed above, the ultrasonic device can be used in an ultrasonic degassing process. The ultrasonic transducer can generate ultrasonic waves, and the probe attached to the transducer can deliver ultrasonic waves to a bath including molten metals, such as aluminum, copper, zinc, steel, magnesium, and the like, or mixtures and / or combinations thereof (e.g., various alloys including aluminum, copper, zinc, steel, magnesium, etc.).

[0166] In various embodiments of the present invention, a combination of ultrasonic degassing and ultrasonic grain refinement is used. As described below, the use of a combination of ultrasonic degassing and ultrasonic grain refinement provides advantages both individually and in combination. Although not limited to the following discussion, the following discussion provides an understanding of the unique effects of the combination of ultrasonic degassing and ultrasonic grain refinement, bringing (multiple) improvements in the overall quality of the casting product that would not be expected when used alone. These effects were achieved by the inventors in the development of this combined ultrasonic treatment.

[0167] In ultrasonic degassing, chlorine chemicals (used when ultrasonic degassing is not used) are eliminated from the metal casting process. When chlorine is present as a chemical in the molten metal bath, it can react and form strong chemical bonds with other foreign elements in the bath (such as bases that may be present). In the presence of bases, stable salts are formed in the molten metal bath, which can lead to inclusions in the cast metal product, which deteriorate its conductivity and mechanical properties. In the absence of ultrasonic grain refinement, chemical grain refiners such as titanium boride are used, but these materials usually contain bases.

[0168] Thus, in the case of ultrasonic degassing eliminating chlorine as a treatment element, and in the case of ultrasonic grain refining eliminating a grain refiner (alkali source), the likelihood of stable salt formation and resulting inclusion formation in the cast metal product is significantly reduced. In addition, the elimination of these foreign elements as impurities improves the electrical conductivity of the cast metal product. Thus, in one embodiment of the invention, the combination of ultrasonic degassing and ultrasonic grain refining means that the resulting cast product has excellent mechanical and electrical conductivity properties because two of the main sources of impurities are eliminated without replacing one foreign impurity with another.

[0169] Another advantage provided by the combination of ultrasonic degassing and ultrasonic grain refinement relates to the fact that both ultrasonic degassing and ultrasonic grain refinement effectively "stir" the molten bath, homogenizing the molten material. When an alloy of metals is melted and then cooled to solidify, an intermediate phase of the alloy may exist due to the corresponding differences in the melting points of the different alloy ratios. In one embodiment of the present invention, both ultrasonic degassing and ultrasonic grain refinement stir and mix the intermediate phase back into the molten phase.

[0170] All of these advantages allow obtaining a product with a small grain size, with fewer impurities, fewer inclusions, better conductivity, better ductility and higher tensile strength than would be expected when using ultrasonic degassing or ultrasonic grain refining or when replacing one or both with conventional chlorine treatment or when using chemical grain refiners.

[0171] Demonstration of Ultrasonic Grain Refining

[0172] Used Figure 2 and 33A, which has a depth of 10 cm and a width of 8 cm, forms a rectangular slot or channel in the casting wheel 30. The thickness of the flexible metal strip is 6.35 mm. The width of the flexible metal strip is 8 cm. The steel alloy used for the strip is 1010 steel. An ultrasonic frequency of 20 KHz is used at a power of 120 W (per probe), which is supplied to one or two transducers with a vibrating probe in contact with water in the cooling medium. A section of the copper alloy casting wheel is used as a mold. As a cooling medium, water is supplied at close to room temperature and flows through the channel 46 at about 15 liters / minute.

[0173] Molten aluminum is poured at a rate of 40 kg / min, producing a continuous aluminum casting that shows properties consistent with an equiaxed grain structure, but without the addition of grain refiners. In fact, approximately 9 million pounds of aluminum rods are cast and drawn using this technology to final size for wire and cable applications.

[0174] Metal Products

[0175] In one aspect of the invention, a product comprising a cast metal composition can be formed in a channel of a casting wheel, or in a casting structure discussed above, without the need for a grain refiner and still having a sub-millimeter grain size. Thus, a cast metal composition can be made with less than 5% of a composition comprising a grain refiner and still achieve a sub-millimeter grain size. A cast metal composition can be made with less than 2% of a composition comprising a grain refiner and still achieve a sub-millimeter grain size. A cast metal composition can be made with less than 1% of a composition comprising a grain refiner and still achieve a sub-millimeter grain size. In a preferred composition, the grain refiner is less than 0.5%, or less than 0.2%, or less than 0.1%. A cast metal composition can be made with a composition that does not include a grain refiner and still achieve a sub-millimeter grain size.

[0176] The casting metal composition can have a variety of sub-millimeter particle sizes depending on many factors, including the component, pouring rate, pouring temperature and cooling rate of "pure" or alloy metal. The list of particle sizes available for the present invention includes the following. For aluminum and aluminum alloys, the particle size range is from 200 to 900 microns, or 300 to 800 microns, or 400 to 700 microns, or 500 to 600 microns. For copper or copper alloys, the particle size range is from 200 to 900 microns, or 300 to 800 microns, or 400 to 700 microns, or 500 to 600 microns. For gold, silver, or tin or its alloy, the particle size range is from 200 to 900 microns, or 300 to 800 microns, or 400 to 700 microns, or 500 to 600 microns. For magnesium or magnesium alloys, the particle size ranges from 200 to 900 microns, or 300 to 800 microns, or 400 to 700 microns, or 500 to 600 microns. Although given as ranges, the invention is also capable of intermediate values. In one aspect of the invention, small concentrations (less than 5%) of grain refiners may be added to further reduce the particle size to values ​​between 100 and 500 microns. The casting metal composition may include aluminum, copper, magnesium, zinc, lead, gold, silver, tin, bronze, brass, or alloys thereof.

[0177] The cast metal composition may be drawn or otherwise formed into strips, bars, stock, sheets, wire, billets, and pellets.

[0178] Computerized control

[0179] Figure 1 , the controller 500 in 2, 3 and 4 can be Figure 7 The computer system 1201 shown in FIG. 1201 can be used as a controller 500 to control the casting system described above, or any other casting system or device using the ultrasonic treatment of the present invention. Figure 1 , 2, 3 and 4 are depicted as a single controller, but the controller 500 may include discrete and separate processors that communicate with each other and / or are dedicated to specific control functions.

[0180] Specifically, the controller 500 may be specially programmed to have the function of executing Figure 8 The functional control algorithm is shown in the flow chart.

[0181] Figure 8 A flow chart is depicted, elements of which may be programmed or stored in one of the computer readable media or data storage devices discussed below. Figure 81804, the programmed element will indicate the operation of cooling the molten metal containment structure, for example by passing a liquid medium through a cooling channel near the molten metal containment structure. At step element 1806, the programmed element will indicate the operation of coupling vibration energy into the molten metal. At this element, as discussed above, the vibration energy will have a frequency and power that induces nucleation sites in the molten metal.

[0182] Elements such as molten metal temperature, pouring rate, cooling flow through the cooling channel passages, and mold cooling, and elements involved in controlling and drawing the cast product through the machine (including controlling the power and frequency of the vibration energy source) will be programmed in a standard software language (discussed below) to produce a dedicated processor containing instructions to use the method of the present invention to induce nucleation sites in a metal product.

[0183] More specifically, Figure 7 The computer system 1201 shown in the figure includes a bus 1202 or other communication mechanism for communicating information, and a processor 1203 connected to the bus 1202 for processing information. The computer system 1201 also includes a main memory 1204 connected to the bus 1202 to store information and instructions to be executed by the processor 1203, such as a random access memory (RAM) or other dynamic storage device (for example, dynamic RAM (DRAM), static RAM (SRAM) and synchronous DRAM (SDRAM)). In addition, the main memory 1204 can be used to store temporary variables or other intermediate information during the execution of instructions by the processor 1203. The computer system 1201 also includes a read-only memory (ROM) 1205 or other static storage device (for example, a programmable read-only memory (RAM), an erasable PROM (EPROM) and an electrically erasable PROM (EEPROM)) connected to the bus 1202 to store static information and instructions for the processor 1203.

[0184] The computer system 1201 also includes a disk controller 1206 coupled to the bus 1202 to control one or more storage devices for storing information and instructions, such as a magnetic hard disk 1207 and a removable media drive 1208 (e.g., a floppy disk drive, a read-only optical drive, a read / write optical drive, an optical disk library, a tape drive, and a removable magneto-optical drive). The storage devices may be added to the computer system 1201 using a suitable device interface (e.g., small computer system interface (SCSI), integrated device electronics (IDE), enhanced IDE (E-IDE), direct memory access (DMA), or high-speed DMA).

[0185] Computer system 1201 may also include special purpose logic devices (eg, application specific integrated circuits (ASICs)) or configurable logic devices (eg, simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)).

[0186] The computer system 1201 may also include a display controller 1209 coupled to the bus 1202 to control a display, such as a cathode ray tube (CRT) or a liquid crystal display (LCD), for displaying information to a computer user. The computer system includes input devices, such as a keyboard and pointing device, for interacting with a computer user (e.g., a user interacting with the controller 500) and providing information to the processor 1203.

[0187] The computer system 1201 performs some or all of the process steps of the present invention (e.g., such as those described with respect to providing vibrational energy to a liquid metal in a thermally stable state) in response to the processor 1203 executing one or more sequences of one or more instructions contained in a memory, such as a main memory 1204. Such instructions may be read into the main memory 1204 from another computer-readable medium, such as a hard disk 1207 or a removable media drive 1208. One or more processors in a multi-processing arrangement may also be used to execute the sequences of instructions contained in the main memory 1204. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, the embodiments are not limited to any specific combination of hardware circuitry and software.

[0188] Computer system 1201 includes at least one computer readable medium or memory for holding instructions programmed according to the teachings of the present invention and for containing data structures, tables, records or other data described herein. Examples of computer readable media are optical disks, hard disks, floppy disks, tapes, magneto-optical disks, PROMs (EPROMs, EEPROMs, flash EPROMs), DRAMs, SRAMs, SDRAMs, or any other magnetic media, optical disks (e.g., CD-ROMs), or any other optical media, or other physical media, carrier waves (described below), or any other media from which a computer can read.

[0189] The present invention includes software stored on any one or combination of computer readable media for controlling the computer system 1201, for driving one or more devices for implementing the present invention, and for allowing the computer system 1201 to interact with a human user. Such software may include, but is not limited to, device drivers, operating systems, development tools, and application software. Such computer readable media also include the computer program product of the present invention for performing all or part (if the processing is distributed) of the processing performed in implementing the present invention.

[0190] The computer code device of the present invention can be any translatable or executable code mechanism, including but not limited to scripts, translatable programs, dynamic link libraries (DDLs), JAVA classes, and complete executable programs. In addition, parts of the processing of the present invention can be distributed for better performance, reliability and / or cost.

[0191] As used herein, the term "computer-readable medium" refers to any medium that participates in providing instructions to the processor 1203 for execution. Computer-readable media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. For example, volatile media include optical, magnetic, and magneto-optical disks, such as hard disk 1207 and removable media drive 1208. Volatile media include dynamic memory, such as main memory 1204. Transmission media include coaxial cables, copper wire, or optical fiber, including the wires that make up bus 1202. Transmission media can also take the form of acoustic or light waves, such as those generated during radio wave or infrared data transmission.

[0192] The computer system 1201 may also include a communication interface 1213 connected to the bus 1202. The communication interface 1213 provides a two-way data communication connected to a network link 1214, which is connected to a local area network (LAN) 1215 or another communication network 1216 such as the Internet. For example, the communication interface 1213 can be a network interface card attached to any packet switching LAN. As another example, the communication interface 1213 can be an asymmetric digital subscriber line (ADSL) card, an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of communication line. A wireless link can also be implemented. In any such implementation, the communication interface 123 sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

[0193] The network link 1214 typically provides data communications to other data devices via one or more networks. For example, the network link 1214 may provide a connection to another computer via a local area network 1215 (e.g., LAN) or via equipment operated by a service provider, which provides communication services via a communication network 1216. In one embodiment, this capability allows the present invention to have multiple controllers 500 networked together for purposes such as factory automation or quality control. The local area network 1215 and the communication network 1216 use, for example, electrical, electromagnetic, or optical signals that carry digital data streams, and associated physical layers (e.g., CAT5 cables, coaxial cables, optical fibers, etc.). Signals passing through various networks, as well as signals on the network link 1214 and through the communication interface 1213 that carries digital data to and from the computer system 1201, may be implemented in baseband signals or carrier-based signals. Baseband signals transmit digital signals as unmodulated electrical pulses that describe a digital data bit stream, where the term "bit" is broadly understood to mean a symbol, where each symbol transmits at least one or more information bits. Digital data may also be used to modulate a carrier wave, e.g., to shift a key signal in amplitude, phase, and / or frequency, which propagates on a conductive medium, or as an electromagnetic wave transmitted through a propagation medium. Thus, digital data may be sent across a "wired" communication channel as unmodulated baseband data, and / or by modulating a carrier wave to be sent in a predetermined frequency band different from baseband. Computer system 1201 may transmit and receive data, including program code, via network(s) 1215 and 1216, network link 1214, and communication interface 1213. In addition, network link 1214 may provide a connection to a mobile device 1217 (e.g., a personal digital assistant (PDA), a notebook computer, or a cellular phone) via LAN 1215.

[0194] More specifically, in one embodiment of the present invention, a continuous casting and rolling system (CCRS) is provided that can continuously produce pure electrical conductor grade aluminum rods and alloy conductor grade aluminum rod coils directly from molten metal. The CCRS can use one or more computer systems 1201 (described above) to implement control, monitoring and data storage.

[0195] In one embodiment of the present invention, to facilitate the production of high quality aluminum bars, an advanced computer monitoring and data acquisition (SCADA) system monitors and / or controls the rolling mill (ie, CCRS). Additional variables and parameters of the system can be displayed, plotted, stored and analyzed for quality control.

[0196] In one embodiment of the invention, one or more of the following post-production testing processes are captured in a data acquisition system.

[0197] Eddy current flaw detectors can be used in production lines to continuously monitor the surface quality of aluminum bars. Inclusions can be detected if located near the surface of the bar because matrix inclusions act as discontinuous defects. During the casting and rolling of aluminum bars, defects in the finished product can come from anywhere in the process. Incorrect melt chemistry and / or excessive hydrogen in the metal can cause defects during the rolling process. The eddy current system is a non-destructive test, and the control system for the CCRS can alert (multiple) operators of any of the defects described above. The eddy current system can detect surface defects and classify the defects as small, medium or large. The eddy current results can be recorded in the SCADA system and tracked to the batch group of aluminum (or other metals processed) and when it was produced.

[0198] Once the rods are coiled at the end of the process, most of the mechanical and electrical properties of the cast aluminum can be measured and recorded in the SCADA system. Product quality tests include: tensile, elongation, and conductivity. Tensile strength is a measure of the strength of a material and is the maximum force a material can withstand under tension before breaking. The elongation value is a measure of the ductility of the material. Conductivity measurements are generally reported as a percentage of the "International Annealed Copper Standard" (IACS). These product quality measurements can be recorded in the SCADA system and traced to the batch of aluminum and when it was produced.

[0199] In addition to eddy current data, surface analysis can be performed using a twist test. Cast aluminum rods undergo a controlled twist test. Defects associated with improper solidification, inclusions, and longitudinal defects created during the rolling process are magnified and revealed on the twisted rods. Generally, these defects are revealed in the form of seams parallel to the rolling direction. A series of parallel lines after the rod is twisted clockwise and counterclockwise indicates that the sample is uniform, while non-uniformities in the casting process will result in fluctuating lines. The results of the twist test can be recorded in a SCADA system and tracked to the batch of aluminum and when it was produced.

[0200] Sample analysis

[0201] The samples discussed below were made with the CCR system described above. The casting and rolling process for producing the samples begins with a continuous flow of molten aluminum from a melting and holding furnace system, which is transported to an in-line chemical grain refinement system or the ultrasonic grain refinement system described above through a refractory lined launder system. In addition, the CCR system includes the ultrasonic degassing system described above, which uses ultrasonic waves and a purge gas to remove dissolved hydrogen or other gases from the molten aluminum. The metal flows from the degasser to a molten metal filter having a porous ceramic element, which further reduces inclusions in the molten metal. The launder system then transports the molten aluminum to a tundish. From the tundish, the molten aluminum is poured into a mold formed by a copper casting ring and a peripheral groove of a steel strip, as described above. Water distributed through nozzles of a multi-zone water manifold cools the molten aluminum into a solid cast rod using a magnetic flowmeter for critical zones. Continuous aluminum cast bars are pushed out of the casting ring onto a bar extraction conveyor until the rolling mill.

[0202] The rolling mill consists of independently driven rolling stands that reduce the diameter of the bars. The bars are then sent to a drawing mill where they are drawn to a predetermined diameter and then coiled. Once the bars are coiled at the end of the process, the mechanical and electrical properties of the cast aluminum are measured. Quality tests include: tensile, elongation, and conductivity. Tensile strength is a measure of the strength of a material and is the maximum force a material can withstand under tension before breaking. The elongation value is a measure of the ductility of the material. Conductivity measurements are generally reported as a percentage of the "International Annealed Copper Standard" (IACS).

[0203] 1) Tensile strength is a measure of the strength of a material and is the maximum force a material can withstand under tension before breaking. Tensile and elongation measurements are performed on the same sample. Select a 10" standard length sample for tensile and elongation measurements. Insert the bar sample into the tensile machine. Place the handle at the 10" scale mark. Tensile Strength = Breaking Force (lbs) / Cross-sectional Area (πr 2 ), where r (inches) is the radius of the bar.

[0204] 2) % Elongation = ((L1-L2) / L1)X100. L1 is the initial gauge length of the material, and L2 is the final length obtained by putting two broken samples from the tensile test together and measuring the failure that occurred. In general, the more ductile the material, the more necking will be observed in the tensile sample.

[0205] 3) Conductivity: Conductivity measurements are generally reported as a percentage of the "International Annealed Copper Standard" (IACS). Conductivity measurements are performed using a Kelvin Bridge, and details are provided in ASTM B193-02. IACS is a unit of electrical conductivity for metals and alloys relative to a standard annealed copper conductor; an IACS value of 100% refers to a conductivity of 5.80×107 Siemens / meter (58.0 MS / m) at 20°C.

[0206] The continuous rod process as described above is useful not only for producing electrical grade aluminum conductors, but also for mechanical aluminum alloys using ultrasonic grain refinement and ultrasonic degassing.For testing the ultrasonic grain refinement process, cast rod samples were collected and etched.

[0207] A comparative analysis of the rod properties was performed between the rods cast using the ultrasonic grain refinement process and the rods cast using the conventional TIBOR grain refiner. Table 1 shows the results for the rods treated using the ultrasonic grain refiner vs. the rods treated using the TIBOR grain refiner.

[0208] Table 1: Quality Test: Ultrasonic Grain Refining vs. Chemical Grain Refining

[0209]

[0210] a: 1000 pounds per square inch; b: percent elongation; c: reported as % IACS; d: average of 13 bar coils Defects associated with improper solidification, inclusions, and longitudinal defects created during the rolling process are magnified and revealed on twisted bars. In general, these defects are revealed in the form of seams parallel to the rolling direction. A series of parallel lines after clockwise and counterclockwise twisting of the bar indicates that the sample is uniform, while non-uniformities in the casting process will result in wavy lines.

[0211] The data in Table 2 below indicate that very few defects were produced using ultrasound. Although no definitive conclusions can be drawn, at least from this set of data points, the number of surface defects observed by the eddy current tester is lower than that of the material treated using ultrasound.

[0212] Table 2: Defect analysis: ultrasonic grain refinement vs. chemical grain refinement

[0213]

[0214] The twist test results showed that the surface quality of the ultrasonically grain refined bars was as good as that of bars produced using chemical grain refiners. After the ultrasonic grain refiner was installed on the continuous rod (CR) process, the chemical grain refiners were reduced to zero while producing high-quality cast bars. The hot rolled bars were then drawn into various wire sizes ranging from 0.1053" to 0.1878". The wires were then processed into overhead transmission cables.

[0215] There are two separate conductors that the product is available in: Aluminum Conductor Steel Supported (ACSS) or Aluminum Conductor Steel Reinforced (ACSR). The only difference between the two processes of making the conductors is that the ACSS aluminum wires are annealed after stranding.

[0216] Fig.10The following is a flow chart of the ACSR wire process. It shows the conversion of pure molten aluminum into aluminum wire to be used in ACSR wire. The first step in the conversion process is to convert the molten aluminum into aluminum rods. In the next step, the rods are drawn through several dies, and depending on the end diameter, this can be done by one or more draws. Once the rods are drawn to the final diameter, the wires are wound onto reels with weights ranging from 200 to 500 pounds. These individual reels are twisted around steel strands into ACSR cables, which contain several independent aluminum strands. The number of strands and the diameter of each strand will depend on customer needs.

[0217] Fig.11 Figure 1 is a process flow chart for ACSS wire. It shows the conversion of pure molten aluminum into aluminum wire to be used in ACSS wire. The first step in the conversion process is to process the molten aluminum into aluminum rods. In the next step, the rods are drawn through several dies, and depending on the end diameter, this can be done by one or more draws. Once the rods are drawn to the final diameter, the wires are wound onto reels with weights ranging between 200 and 500 pounds. These individual reels are twisted around steel strands into ACSS cables, which contain several independent aluminum strands. The number of strands and the diameter of each strand will depend on customer needs. One difference between ACSR and ACSS cables is that once the aluminum is twisted around the steel cable, the entire cable is heat treated in a furnace to bring the aluminum to an extremely soft state. It is important to note that in ACSR, the strength of the cable comes from the combination of strength due to the aluminum cable and the steel cable, while in ACSS cables, most of the strength comes from the steel within the ACSS cable.

[0218] Fig.12 is an aluminum strip process flow diagram, where the strip is ultimately processed into metal clad wire. It shows that the first step is to convert the molten aluminum into aluminum rods. After this, the rod is rolled through several rolling dies to convert it into a strip, which is generally about 0.375" wide and about 0.015 to 0.018" thick. The rolled strip is processed into annular pads, which weigh about 600 pounds. It is important to note that other widths and thicknesses can also be produced using the rolling process, but 0.375" wide and 0.015 to 0.018" thick are the most common. These pads are then heat treated in a furnace to bring the pads to an intermediate annealed state. In this state, the aluminum is neither completely hard nor in an extremely soft state. The strips are then used as sheaths assembled into interlocking metal strips (strips), which surround one or more insulated circuit conductors.

[0219] The comparative analysis shown below based on these processes was done on aluminum drawn wire treated with the ultrasonic grain refining process and aluminum wire treated using conventional TIBOR grain refiner.The drawn samples met all specifications set forth in the ASTM standard for 1350 electrical conductor wire.

[0220] Properties of conventional bars including TIBOR chemical grain refiner

[0221]

[0222]

[0223] Properties of Ultrasonic Treated Rods

[0224]

[0225] Processing conditions for ultrasonically treated rods

[0226]

[0227] *Alloy designations are based on Aluminum Association specifications

[0228] **Aluminum conductor steel support

[0229] ***Aluminum conductor steel reinforcement

[0230] A. 1000 pounds per square inch

[0231] B. Tensile strength in MPa

[0232] C. Percent elongation

[0233] D. International Annealed Copper Standard

[0234] *All length dimensions are in inches.

[0235] Fig.15 Comparison of micrographs of aluminum 1350EC alloy showing the grain structure of castings without chemical grain refiners, with grain refiners and with ultrasonic grain refinement only.

[0236] Fig.16 TABLE 1 is a tabular comparison of conventional 1350EC aluminum alloy rod (with chemical grain refiner) and 1350EC aluminum alloy rod (with ultrasonic grain refinement).

[0237] Fig.17 Tabular comparison of conventional ACSR aluminum wire 0.130" diameter (with chemical grain refiner) versus ACSR aluminum wire 0.130" diameter (with ultrasonic grain refinement).

[0238] Fig.18 A tabular comparison of conventional 8176EEE aluminum alloy rod (with chemical grain refiner) and 8176EEE aluminum alloy rod (with ultrasonic grain refinement).

[0239] Fig.19A tabular comparison of conventional 5154 aluminum alloy rod (with chemical grain refiner) and 5154 aluminum alloy rod (with ultrasonic grain refinement).

[0240] Fig. 20 A tabular comparison of conventional 5154 aluminum alloy bar (with chemical grain refiner) and 5154 aluminum alloy bar (with ultrasonic grain refinement).

[0241] Fig.21 A tabular graph of the properties of 5356 aluminum alloy rod (with ultrasonic grain refinement).

[0242] Summary of the Invention

[0243] The following statements of the invention provide one or more features of the invention and do not limit the scope of the invention.

[0244] Statement 1. A molten metal processing device for a casting wheel on a casting machine, comprising: an assembly mounted on (or coupled to) the casting wheel, including at least one vibration energy source that supplies (e.g., has a configuration in which it supplies) vibration energy (e.g., ultrasonic, mechanical drive, and / or acoustic energy supplied directly or indirectly) to molten metal cast in the casting wheel while the molten metal in the casting wheel is cooling, a support device that holds the at least one vibration energy source, and optionally, a guide device that guides the assembly relative to movement of the casting wheel.

[0245] Statement 2. The device of statement 1, wherein the support device includes a housing including cooling passages for conveying a cooling medium therethrough.

[0246] Statement 3. The apparatus of Statement 2, wherein the cooling passage comprises said cooling medium, which comprises at least one of water, gas, liquid metal, and engine oil.

[0247] Statement 4. The device of Statement 1, 2, 3, or 4, wherein the at least one vibrational energy source comprises at least one ultrasonic transducer, at least one mechanically driven vibrator, or a combination thereof.

[0248] Statement 5. The device of statement 4, wherein the ultrasonic transducer (e.g., a piezoelectric element) is configured to provide vibration energy in a frequency range of up to 400 kHz, or wherein the transducer (e.g., a magnetostrictive element) is configured to provide vibration energy in a frequency range of 20 to 200 kHz.

[0249] Statement 6. The device of Statement 1, 2, or 3, wherein the mechanically driven vibrator comprises a plurality of mechanically driven vibrators.

[0250] Statement 7. The device of statement 4, wherein the mechanically driven vibrator is configured to provide vibration energy in a frequency range of up to 10 KHz, or wherein the mechanically driven vibrator is configured to provide vibration energy in a frequency range of 8,000 to 15,000 per minute.

[0251] Statement 8a. The apparatus of Statement 1, wherein the casting wheel includes a band that confines the molten metal in a channel of the casting wheel.

[0252] Statement 8b. The apparatus of any of Statements 1-7, wherein the assembly is positioned above the casting wheel and has a passage in the housing for the belt to confine the molten metal in the channel of the casting wheel to pass therethrough.

[0253] Statement 9. The apparatus of Statement 8, wherein the belt is guided along the housing to allow cooling medium to flow from the cooling channel along a side of the belt opposite the molten metal.

[0254] Statement 10. The device of any of Statements 1-9, wherein the support device comprises at least one or more of niobium, niobium alloys, titanium, titanium alloys, tantalum, tantalum alloys, copper, copper alloys, rhenium, rhenium alloys, steel, molybdenum, molybdenum alloys, stainless steel, ceramics, composites, polymers, or metals.

[0255] Statement 11. The device of statement 10, wherein the ceramic comprises silicon nitride ceramic.

[0256] Statement 12. The device of statement 11, wherein the silicon nitride ceramic comprises SIALON.

[0257] Statement 13. The apparatus of any of Statements 1-12, wherein the housing comprises a refractory material.

[0258] Statement 14. The apparatus of statement 13, wherein the refractory material comprises at least one of copper, niobium, niobium and molybdenum, tantalum, tungsten, and rhenium, and alloys thereof.

[0259] Statement 15. The apparatus of statement 14, wherein the refractory material comprises one or more of silicon, oxygen, or nitrogen.

[0260] Statement 16. The device of any of Statements 1-15, wherein the at least one vibrational energy source comprises more than one vibrational energy source in contact with a cooling medium; for example, in contact with a cooling medium flowing through a support device or a guide device.

[0261] Statement 17. The device of Statement 16, wherein the at least one vibrational energy source comprises at least one vibration probe inserted into a cooling channel in the support device.

[0262] Statement 18. The device of any of Statements 1-3 and 6-15, wherein the at least one vibrational energy source comprises at least one vibrating probe in contact with the support device.

[0263] Statement 19. The device of any of Statements 1-3 and 6-15, wherein the at least one vibration energy source comprises at least one vibrating probe in contact with a belt at a base of the support device.

[0264] Statement 20. The device of any of Statements 1-19, wherein the at least one vibrational energy source comprises a plurality of vibrational energy sources distributed at different locations in the support device.

[0265] Statement 21. The device of any of Statements 1-20, wherein the guide device is disposed on a belt on a rim of the casting wheel.

[0266] Statement 22. A method for forming a metal product, comprising:

[0267] providing molten metal into a containment structure of a casting machine;

[0268] cooling the molten metal in the containment structure, and

[0269] During said cooling, vibrational energy is coupled into the molten metal in the containment structure.

[0270] Statement 23. The method of statement 22, wherein providing the molten metal comprises pouring the molten metal into a channel in the casting wheel.

[0271] Statement 24. The method of Statement 22 or 23, wherein coupling vibrational energy comprises supplying the vibrational energy from at least one of an ultrasonic transducer or a magnetostrictive transducer.

[0272] Statement 25. The method of statement 24, wherein supplying said vibrational energy comprises providing vibrational energy at a frequency in the range of from 5 to 40 kHz.

[0273] Statement 26. The method of Statement 22 or 23, wherein coupling vibrational energy comprises supplying said vibrational energy from a mechanically driven vibrator.

[0274] Statement 27. The method of statement 26, wherein supplying said vibrational energy comprises providing vibrational energy at a frequency range of 8,000 to 15,000 vibrations per minute or up to 10 KHz.

[0275] Statement 28. The method of any of Statements 22-27, wherein cooling comprises cooling the molten metal by applying at least one of water, gas, liquid metal, and engine oil to a containment structure that holds the molten metal.

[0276] Statement 29. The method of any of Statements 22-28, wherein providing molten metal comprises delivering the molten metal into a mold.

[0277] Statement 30. The method of any of Statements 22-29, wherein providing molten metal comprises delivering the molten metal into a continuous casting mold.

[0278] Statement 31. The method of any of Statements 22-30, wherein providing molten metal comprises delivering the molten metal into a horizontal or vertical casting mold.

[0279] Statement 32. A casting machine comprising a casting mold configured to cool molten metal, and the molten metal processing device of any of Statements 1-21.

[0280] Statement 33. The machine of statement 32, wherein the mold comprises a continuous casting mold.

[0281] Statement 34. The machine of Statement 32 or 33, wherein the mold comprises a horizontal or vertical casting mold.

[0282] Statement 35. A casting machine comprising: a molten metal containment structure configured to cool molten metal; and a vibration energy source attached to the molten metal containment structure and configured to couple vibration energy to the molten metal at a frequency ranging up to 400 kHz.

[0283] Statement 36. A casting machine comprising: a molten metal containment structure configured to cool molten metal; and a mechanically driven vibration energy source attached to the molten metal containment structure and configured to couple vibration energy at a frequency ranging up to 10 KHz (including the range from 0 to 15,000 vibrations per minute and 8,000 to 15,000 vibrations per minute) to the molten metal.

[0284] Statement 37. A system for forming a metal product, comprising: a device for pouring molten metal into a molten metal containment structure; a device for cooling the molten metal containment structure; a device for coupling vibrational energy to the molten metal at a frequency ranging up to 400 KHz (including a range from 0 to 15,000 vibrations per minute, 8,000 to 15,000 vibrations per minute, up to 10 KHz, 15 to 40 KHz, or 20 to 200 kHz); and a controller, which includes data inputs and control outputs and is programmed with a control algorithm that allows operation of any of the step elements recited in statements 22-31.

[0285] Statement 38. A system for forming a metal product, comprising: a molten metal processing apparatus as in any one of Statements 1-21; and a controller including data inputs and control outputs and programmed with a control algorithm that allows any one of the step elements described in Statements 22-31.

[0286] Statement 39. A system for forming a metal product, comprising: an assembly coupled to a casting wheel, the assembly comprising a housing containing a cooling medium so that molten metal cast in the casting wheel is cooled by the cooling medium, and means for guiding the assembly relative to movement of the casting wheel.

[0287] Statement 40. The system of statement 38, comprising any of the elements defined in statements 2-3, 8-15, and 21.

[0288] Statement 41. A molten metal processing device for a casting mill, comprising: at least one vibration energy source that supplies vibration energy to molten metal cast in a casting wheel while the molten metal in the casting wheel is cooling; and a support device that holds the vibration energy source.

[0289] Statement 42. The apparatus of statement 41, comprising any of the elements defined in statements 4-15.

[0290] Statement 43. A molten metal processing device for a casting wheel on a casting machine, comprising: an assembly coupled to the casting wheel, including 1) at least one vibration energy source that supplies vibration energy to molten metal cast in the casting wheel while the molten metal in the casting wheel is cooling, 2) support means for holding the at least one vibration energy source, and 3) optional guide means for guiding the assembly relative to movement of the casting wheel.

[0291] Statement 44. The apparatus of Statement 43, wherein said at least one vibrational energy source supplies vibrational energy directly into the molten metal being cast in the casting wheel.

[0292] Statement 45. The apparatus of Statement 43, wherein said at least one vibrational energy source supplies vibrational energy indirectly to molten metal cast in the casting wheel.

[0293] Statement 46. A molten metal processing device for a casting mill, comprising: at least one vibration energy source that supplies vibration energy to molten metal cast in a casting wheel through an inserted probe while the molten metal in the casting wheel is cooling; and a support device that holds the vibration energy source, wherein the vibration energy reduces segregation of the molten metal as the metal solidifies.

[0294] Statement 47. The apparatus of statement 46, comprising any of the elements defined in statements 2-21.

[0295] Statement 48. A molten metal processing device for a casting mill, comprising: at least one vibration energy source that supplies acoustic energy to molten metal cast in a casting wheel while the molten metal in the casting wheel is cooling; and a support device that holds the vibration energy source.

[0296] Statement 49. The device of statement 48, wherein the at least one vibrational energy source comprises an audio amplifier.

[0297] Statement 50. The apparatus of statement 49, wherein the audio amplifier couples the vibrational energy to the molten metal via a gaseous medium.

[0298] Statement 51. The device of statement 49, wherein the audio amplifier couples the vibrational energy to a support structure containing the molten metal via a gaseous medium.

[0299] Statement 52. A method for refining grain size, comprising: supplying vibration energy to a molten metal while cooling the molten metal; breaking up dendrites formed in the molten metal to generate nuclei in the molten metal.

[0300] Statement 53. The method of statement 52, wherein the vibrational energy comprises one or more of ultrasonic vibrations, mechanically driven vibrations, or acoustic vibrations.

[0301] Statement 54. The method of statement 52, wherein the nucleus source in the molten metal does not include foreign impurities.

[0302] Statement 55. The method of statement 52, wherein a portion of the molten metal is supercooled to produce said dendrites.

[0303] Statement 56. A molten metal processing apparatus comprising:

[0304] a source of molten metal;

[0305] An ultrasonic degasser comprising an ultrasonic probe inserted into the molten metal;

[0306] a mold for receiving molten metal;

[0307] Components mounted on the mold, including:

[0308] at least one vibration energy source that supplies vibration energy to the molten metal cast in the casting wheel while the molten metal in the mold is cooling, and

[0309] A support device holds the at least one vibrational energy source.

[0310] Statement 57. The apparatus of Statement 56, wherein the casting mold comprises a component of a casting wheel of a casting machine.

[0311] Statement 58. The device of statement 56, wherein the support device includes a housing including cooling passages for conveying a cooling medium therethrough.

[0312] Statement 59. The apparatus of Statement 58, wherein the cooling passage comprises said cooling medium comprising at least one of water, gas, liquid metal, and engine oil.

[0313] Statement 60. The device of statement 56, wherein the at least one vibrational energy source comprises an ultrasonic transducer.

[0314] Statement 61. The device of statement 56, wherein the at least one vibrational energy source comprises a mechanically driven vibrator.

[0315] Statement 62. The method of statement 61, wherein the mechanically driven vibrator is configured to provide vibration energy in a frequency range up to 10 Khz.

[0316] Statement 63. The apparatus of statement 56, wherein the casting mold comprises a band that confines the molten metal in a channel of the casting wheel.

[0317] Statement 64. The apparatus of statement 63, wherein the assembly is positioned above the casting wheel and has a passage in the housing for the belt to confine the molten metal in the channel of the casting wheel to pass therethrough.

[0318] Statement 65. The apparatus of Statement 64, wherein the belt is directed along the housing to allow cooling medium to flow from the cooling channel along a side of the belt opposite the molten metal.

[0319] Statement 66. The device of statement 56, wherein the support device comprises at least one or more of niobium, niobium alloys, titanium, titanium alloys, tantalum, tantalum alloys, copper, copper alloys, rhenium, rhenium alloys, steel, molybdenum, molybdenum alloys, stainless steel, ceramics, composites, polymers, or metals.

[0320] Statement 67. The device of statement 66, wherein the ceramic comprises a silicon nitride ceramic.

[0321] Statement 68. The device of statement 67, wherein the silicon nitride ceramic comprises SIALON.

[0322] Statement 69. The apparatus of statement 64, wherein the housing comprises a refractory material.

[0323] Statement 70. The apparatus of statement 69, wherein the refractory material comprises at least one of copper, niobium, niobium and molybdenum, tantalum, tungsten, and rhenium, and alloys thereof.

[0324] Statement 71. The apparatus of statement 69, wherein the refractory material comprises one or more of silicon, oxygen, or nitrogen.

[0325] Statement 72. The device of statement 56, wherein the at least one vibrational energy source comprises more than one vibrational energy source in contact with the cooling medium.

[0326] Statement 73. The device of statement 72, wherein the at least one vibrational energy source comprises at least one vibration probe inserted into a cooling channel in the support device.

[0327] Statement 74. The device of statement 56, wherein the at least one vibrational energy source comprises at least one vibrating probe in contact with the support device.

[0328] Statement 75. The device of statement 56, wherein the at least one vibration energy source comprises at least one vibrating probe in direct contact with the belt at the base of the support device.

[0329] Statement 76. The device of statement 56, wherein the at least one vibrational energy source comprises a plurality of vibrational energy sources distributed at different locations in the support device.

[0330] Statement 77. The apparatus of Statement 57, further comprising guide means for guiding the assembly relative to movement of the casting wheel.

[0331] Statement 78. The device of statement 72, wherein the guide device is disposed on a belt on the rim of the casting wheel.

[0332] Statement 79. The apparatus of statement 56, wherein the ultrasonic degasser comprises:

[0333] An elongated probe including a first end and a second end, the first end being attached to the ultrasonic transducer and the second end including a tip, and a purge gas delivery including a purge gas inlet and a purge gas outlet, the purge gas outlet being disposed at the tip of the elongated probe for introducing a purge gas into the molten metal.

[0334] Statement 80. The device of statement 56, wherein the elongated probe comprises ceramic.

[0335] Statement 81. A metal product comprising:

[0336] A cast metal composition having a sub-millimeter grain size and including less than 0.5% grain refiner and having at least one of the following properties:

[0337] At 100 lbs / in 2 The elongation under the stretching force ranges from 10% to 30%,

[0338] Tensile strength ranging from 50 to 300 MPa; or

[0339] Conductivities ranging from 45% to 75% IAC, where IAC is the unit of conductivity in percent of standard annealed copper conductor.

[0340] Statement 82. The product of statement 81, wherein the composition includes less than 0.2% of a grain refiner.

[0341] Statement 83. The product of statement 81, wherein the composition includes less than 0.1% of a grain refiner.

[0342] Statement 84. The product of statement 81, wherein the composition does not include a grain refiner.

[0343] Statement 85. The product of statement 81, wherein the composition comprises at least one of aluminum, copper, magnesium, zinc, lead, gold, silver, tin, bronze, brass, and alloys thereof.

[0344] Statement 86. The product of statement 81, wherein the composition is formed into at least one of a bar, a rod, a rod, a sheet, a wire, a billet, and a pellet.

[0345] Statement 87. The product of statement 81, wherein the elongation ranges from 15% to 25%, or the tensile strength ranges from 100 to 200 MPa, or the electrical conductivity ranges from 50% to 70% of IAC.

[0346] Statement 88. The product of statement 81, wherein the elongation ranges from 17% to 20%, or the tensile strength ranges from 150 to 175 MPa, or the electrical conductivity ranges from 55% to 65% of IAC.

[0347] Statement 89. The product of statement 81, wherein the elongation ranges from 18% to 19%, or the tensile strength ranges from 160 to 165 MPa, or the electrical conductivity ranges from 60% to 62% of IAC.

[0348] Statement 90. The product of any one of Statements 81, 87, 88, and 89, wherein the composition comprises aluminum or an aluminum alloy.

[0349] Statement 91. The product of statement 90, wherein the aluminum or aluminum alloy comprises steel reinforced strands.

[0350] Statement 92. The product of statement 90, wherein the aluminum or aluminum alloy comprises a steel-backed strand.

[0351] Statement 92. A metal product made by one or more of the process steps set forth in Statements 52-55 and comprising a cast metal component.

[0352] Statement 93. The product of statement 92, wherein the cast metal component has a sub-millimeter grain size and includes less than 0.5% grain refiner therein.

[0353] Statement 94. The product of statement 92, wherein the metal product has at least one of the following properties:

[0354] At 100 lbs / in 2 The elongation under the stretching force ranges from 10% to 30%,

[0355] Tensile strength ranging from 50 to 300 MPa; or

[0356] Conductivities ranging from 45% to 75% IAC, where IAC is the unit of conductivity in percent of standard annealed copper conductor.

[0357] Statement 95. The product of statement 92, wherein the composition includes less than 0.2% of a grain refiner.

[0358] Statement 96. The product of statement 92, wherein the composition includes less than 0.1% of a grain refiner.

[0359] Statement 97. The product of statement 92, wherein the composition does not include a grain refiner.

[0360] Statement 98. The product of statement 92, wherein the composition comprises at least one of aluminum, copper, magnesium, zinc, lead, gold, silver, tin, bronze, brass, and alloys thereof.

[0361] Statement 99. The product of statement 92, wherein the composition is formed into at least one of a bar, a rod, a rod, a sheet, a wire, a billet, and a pellet.

[0362] Statement 100. The product of statement 92, wherein the elongation ranges from 15% to 25%, or the tensile strength ranges from 100 to 200 MPa, or the conductivity ranges from 50% to 70% of IAC.

[0363] Statement 101. The product of statement 92, wherein the elongation ranges from 17% to 20%, or the tensile strength ranges from 150 to 175 MPa, or the electrical conductivity ranges from 55% to 65% of IAC.

[0364] Statement 102. The product of statement 92, wherein the elongation ranges from 18% to 19%, or the tensile strength ranges from 160 to 165 MPa, or the electrical conductivity ranges from 60% to 62% of IAC.

[0365] Statement 103. The product of statement 92, wherein the composition comprises aluminum or an aluminum alloy.

[0366] Statement 104. The product of statement 103, wherein the aluminum or aluminum alloy comprises steel reinforced strands.

[0367] Statement 105. The product of statement 103, wherein the aluminum or aluminum alloy comprises a steel-backed strand.

[0368] Many modifications and variations of the present invention are possible in light of the above teachings.It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

1. A metal product comprising: A cast metal composition having an equiaxed grain structure with sub-millimeter grain size and including less than 0.1% grain refiner and having at least one of the following properties: At 100 lbs / in 2 The elongation under the stretching force ranges from 10 to 30%, Tensile strength ranging from 50 to 300 MPa; and An electrical conductivity ranging from 45 to 75% of IAC, wherein IAC is a unit of electrical conductivity in percent relative to a standard annealed copper conductor, wherein the product is formed by a method for forming a metal product, the method comprising: providing molten metal to a casting wheel of a casting machine; cooling the molten metal in the casting wheel, and coupling vibration energy into the molten metal in the casting wheel during said cooling via at least one vibration energy source held by a support device, Wherein the support device includes a housing including a cooling channel for conveying a cooling medium therethrough, and the at least one vibration energy source is configured to couple the vibration energy to molten metal in the casting wheel through the cooling medium.

2. The product according to claim 1, wherein The composition does not include a grain refiner therein.

3. The product according to claim 1, wherein: The composition includes at least one of aluminum, copper, magnesium, zinc, lead, gold, silver, tin, bronze, brass, and alloys thereof.

4. The product according to claim 1, wherein: The composition is formed into at least one of a bar, a rod, a sheet, a wire, a billet, and a pellet.

5. The product according to claim 1, wherein The elongation ranges from 15 to 25%, or the tensile strength ranges from 100 to 200 MPa, or the conductivity ranges from 50 to 70% of IAC.

6. The product according to claim 1, wherein: The elongation ranges from 17 to 20%, or the tensile strength ranges from 150 to 175 MPa, or the conductivity ranges from 55 to 65% of IAC.

7. The product according to claim 1, wherein: The elongation ranges from 18 to 19%, or the tensile strength ranges from 160 to 165 MPa, or the conductivity ranges from 60 to 62% of IAC.

8. The product according to any one of claims 1, 5, 6 and 7, wherein The composition includes aluminum or an aluminum alloy.

9. The product according to claim 8, wherein The aluminum or the aluminum alloy includes steel-reinforced strands.

10. The product according to claim 8, wherein: The aluminum or the aluminum alloy comprises a steel-supported strand.

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