43 results about "Direct chill casting" patented technology

A process of producing an aluminum alloy sheet product suitable for forming into automotive parts and exhibiting reduced roping effects. The process involves producing an aluminum alloy sheet product by direct chill casting an aluminum alloy to form a cast ingot, homogenizing the ingot, hot rolling the ingot to form and intermediate gauge product, cold rolling the intermediate gauge product to form a product of final gauge, and subjecting the final gauge product to a solutionizing treatment by heating the product to a solutionizing temperature, followed by a pre-aging step involving cooling the product to a coiling temperature above 50 DEG C., coiling the cooled product at the coiling temperature, and cooling the coiled final gauge product from the coiling temperature above 50 DEG C. to ambient temperature at a rate less than about 10 DEG C. per hour to improve T8X temper characteristics of the product. Additionally, a batch anneal step is carried out on the intermediate gauge product or at an intermediate stage of the cold rolling to reduce or eliminate roping tendencies of the alloy sheet product. To maintain a high T8X response, the alloy used in the process has the following composition: 0.4 to 1.1% by weight magnesium; 0.3 to 1.4% by weight silicon; 0 to 1.0% by weight copper; 0 to 0.4% by weight iron; 0 to 0.15% by weight manganese; 0 to 0.15% weight naturally-occurring impurities (collective total); and the balance aluminum. The invention also relates to a sheet alloy product exhibiting reduced roping effects produced by the indicated process.

The invention provides equipment and a method for casting a plurality of aluminum alloy ingots with small diameters by using vertical direct chilling casting (DC) and relates to the equipment and the method for casting the aluminum alloy ingots, which aim to solve the problems of low consistency of metal temperatures, low water cooling uniformity and high possibility of ingot suspension or tension fracture and flow running in each crystallizer in the process of casting the aluminum alloy ingots with the small diameters by the conventional technology for casting the plurality of aluminum alloy ingots with the small diameters by using the vertical DC. The method comprises the following steps of: communicating all branch outlets on runners with a plurality of upper end inlets of hot top caps correspondingly one by one; communicating the lower end outlet of each hot top cap with a crystallizer inlet of the crystallizer, wherein the distances between a flow storage slot and the runners of all crystallizers are same; heating a heat preserving sleeve to the temperature of between 100 and 150 DEG C; opening the outlet of a smelting furnace, feeding molten aluminum alloy into all the crystallizers through the runners, and performing water cooling; stopping for 5 to 10 seconds after the liquid level of the molten aluminum alloy in the runners reaches a preset position; and moving an ingot guiding device downwards. The surface of each ingot is smooth, does not have cracks and has small segregation tumors, and each ingot does not have air pores, is not loose and has small grains.

A method and apparatus is disclosed for sequentially direct chill casting a composite ingot made of metals having similar freezing ranges. Poor adhesion between the layers and low reliability of casting are addressed by adjusting the position of secondary cooling (created by applying water streams to the emerging ingot) relative to the upper surfaces of the molten metal pools compared to the conventional positions of first application of the secondary cooling. This can be achieved by moving one or more walls of the mold (when the secondary cooling emanates from the bottom of such walls), or adjusting the height of the molten metal pools within the mold and moving cooled divider walls between the pools. The relative temperatures and conditions of the metals at positions where they meet at the metal interface may therefore be optimized.

This invention relates to an apparatus (high shear device) and method for treating liquid metals by intensive melt shearing. The apparatus comprises a stator and a rotor with a small gap between them to provide intensive melt shearing for dispersing efficiently and distributing uniformly gas, liquid and solid phases in liquid metals without severe turbulence at the melt surface. The device can be extended to a multistage high shear pump by arranging individual rotor/stator assemblies either concentrically (one in another) or vertically. The device and high shear pump can be readily integrated into existing casting processes. The device is suitable for use in casting processes including high pressure die casting, low pressure die casting, gravity die casting, sand casting, investment casting, direct chill casting, twin roll casting, and any other casting process which requires liquid metal as a feedstock. In addition, the device is particularly suitable for providing conditioned liquid metal for both shape casting and continuous (or semi-continuous) casting of metallic materials, preparing high quality semi-solid slurries, solidification processing of particulate reinforced metal matrix composites, mixing immiscible metallic liquids and degassing of liquid metals prior to any casting processes.

A method of casting a metal ingot with a microstructure that facilitates further working, such as hot and cold rolling. The metal is cast in a direct chill casting mold, or the equivalent, that directs a spray of coolant liquid onto the outer surface of the ingot to achieve rapid cooling. The coolant is removed from the surface at a location where the emerging embryonic ingot is still not completely solid, such that the latent heat of solidification and the sensible heat of the molten core raises the temperature of the adjacent solid shell to a convergence temperature that is above a transition temperature for in-situ homogenization of the metal. A further conventional homogenization step is then not required. The invention also relates to the heat-treatment of such ingots prior to hot working.

A method for preparing a mould lubricant for use in direct chill casting of reactive metals, including magnesium, magnesium alloys, aluminum, and aluminum alloys, proceeds through combining a casting lubricant and a gaseous oxidation-inhibiting agent in a vessel external from the mold under vacuum conditions. The casting lubricant is selected from a variety of casting oils and casting greases. The gaseous oxidation-inhibiting agent is selected from a variety of inert gases, including sulfur hexafluoride (SF6).

A method and apparatus is disclosed for casting a composite ingot made of metals that are susceptible to surface oxide formation when molten. The method involves co-casting at least two metal layers from at least two molten metal pools formed within a direct chill casting apparatus. During the casting operation, movement of metal oxide formed on the upper surface of at least one of the pools towards an edge of the pool is restrained by an oxide skimmer positioned close to an edge of the pool above an external surface or metal-metal interface of the ingot. The apparatus provides a DC caster with at least one oxide skimmer that operates in this manner.

An adjustable mold for direct chill casting of metals has longitudinally movable end walls which are clamped between the mold side walls during casting. Each end wall is secured to a sliding carriage which supports the end wall and allows it to be moved along the end portions of the side walls. The sliding suspender has a clamping mechanism which applies a clamping force to one or both of the side walls, the force being transversely directed through a center of the end wall. The side walls are pivotable relative to one another to allow clamping and unclamping of the end walls. Preferably, one end of each side wall is pivotable so as to transversely displace the opposite end of the side wall, with the pivoting ends of the respective side walls preferably being opposite one another across the mold.

An aluminum alloy fin stock material comprising about 0.9-1.2 wt% of Si, 0.3-0.5 wt% of Fe, 0.20-0.40 wt% of Cu, 1.0-1.5 wt% of Mn, 0-0.1% of Mg and 0.0-3.0% of Zn, with remainder Al and impurities no more than 0.15 wt%. The aluminum alloy fin stock material is produced in a form of a sheet by a process comprising the steps of direct chill casting an ingot, hot rolling the ingot after the direct chill casting, cold rolling the aluminum alloy to an intermediate thickness, inter-annealing the aluminum alloy cold rolled to an intermediate thickness at a temperature between 200 and 400 DEG C, and cold rolling the material after inter-annealing to achieve % cold work (%CW) of 20 to 40%. The aluminum alloy fin stock material possesses an improved combination of one or more of pre- and/or post-brazes strength, conductivity, sag resistance and corrosion potential. It is useful for fabrication of heat exchanger fins.

The magnesium-contained high-silicon aluminum alloys for use as structural materials, including profiles, bars, sheets, and forgings, are manufactured by a process including the steps of: casting an alloy ingot by direct chill casting, preheating the ingot to disperse eutectic Si phase particles, and thermal-plastic processing and heat-treating to obtain the product with a final shape and a modified microstructure. The aluminum alloys contain 0.2˜2.0 wt % of Mg and 8˜18 wt % of Si, and have homogeneous and fine microstructure, wherein the aluminum matrix is equiaxed with an average grain size less than 6 μm, and the silicon and second phase particles are dispersed with an average size less than 5 μm. Without adding any modifiers, they are low-costly produced by incorporating the direct chill casting with thermal-plastic processing and heat treatment, which give rise to good plasticity and relatively high strength.

The invention discloses a device for preparing an aluminum alloy cast ingot by using an induction coil and permanent magnetism mixing in combination with DC (Direct chill Casting). The device comprises a crystallizer, the induction coil and a permanent magnet mixing unit; the induction coil is located in a crystallizer cooling jacket; a driving motor is arranged at the upper part of the permanentmagnet mixing unit; a magnetism-conductive sleeve is arranged below the driving motor; the magnetism-conductive sleeve is sleeved with a heat insulation jacket; the driving motor and a connecting shaft are assembled together; the bottom end of the connecting shaft is fixedly connected with a permanent magnet; and the connecting shaft and the permanent magnet are located in the magnetism-conductivesleeve. The device can simultaneously utilize the induction coil to generate an electromagnetic field and the permanent magnet to generate a magnetic field in the direct chill casting process, composite field casting is realized through adjustment on parameters of the induction coil and the permanent magnet, uniformity of a melt temperature field and a component field is ensured, uniform and fineingot structures are obtained, center negative segregation and cast ingot cracking phenomena are reduced.

An improved apparatus for direct chill casting of metals includes a mold, a bottom block assembly and a coolant. The mold is configured to surround a molten metal with a mold wall and the mold wall has an outer surface and an inner surface being in contact with the molten metal. The bottom block assembly is arranged at the bottom of the mold and includes a direct chill casting block configured to move away from the mold as the casting forms a solidifying shell of the molten metal. The coolant surrounds the outer surface of the mold wall and is arranged to remove heat away from the molten metal via the inner surface of the mold wall. The outer surface of the mold wall has a circumferential groove filled with a brazing alloy.

An exemplary embodiment of the invention provides a method of direct chill casting a composite metal ingot. The method involves sequentially casting two or more metal layers to form a composite ingot by supplying streams of molten metal to two or more casting chambers within a casting mold of a direct chill casting apparatus. Inlet temperatures of one or more of the streams of molten metal are monitored at a position adjacent to an inlet of a casting chamber fed with the stream, and the inlet temperatures are compared with a predetermined set temperature for the stream to determine if there is any difference. A casting variable that affects molten metal temperatures entering or within the casting chambers (e.g. casting speed) is then adjusted by an amount based on the difference of the compared temperatures to eliminate adverse casting effects caused by the difference of the inlet temperature and the set temperature. Preferably an adjustment is selected that causes the monitored temperature to approach the set temperature. Another exemplary embodiment provides equipment for operation of the method.

The invention provides a magnesium based alloy consisting of at least 94.8% magnesium, 2.5-4.6% neodymium, 0.05-0.40% yttrium, and 0.03-0.65% zirconium, exhibiting good castability, high strength, high corrosion resistance and high creep resistance even at high temperatures. The alloy is suitable for high pressure die casting, sand casting, investment casting, permanent mold casting, twin roll casting, or direct chill casting.