Device and method for preparing bean-shaped Al-37Sn intermediate alloy

Abstract

The invention discloses a preparation device and method of bean-shaped Al-37Sn intermediate alloy, the preparation device comprises a smelted Al-37Sn intermediate alloy induction furnace, a diversion trench, a funnel, a water-cooling copper turntable, a separator, a material collecting bin and a screening machine; one end of the diversion trench is connected with a discharge hole of the induction furnace, and the other end is obliquely downwards arranged above the funnel; the funnel is arranged above the water-cooling copper turntable, and the bottom of the funnel is provided with leaking holes; the water-cooling copper rotating disc and the separator are horizontally located in the material collecting bin, the separator is located in a rotating shaft inner cavity in the middle of the water-cooling copper rotating disc, one end of the separator upwards penetrates out of a rotating shaft, a certain gap is formed between the periphery of the water-cooling copper rotating disc and the inner side of the material collecting bin, and the screening machine is arranged below an outlet of the material collecting bin. By means of the device, the problems that the Sn element of the Al-37Sn intermediate alloy is segregated and is difficult to break can be effectively solved, the Al-37Sn intermediate alloy can be added into smelting of the titanium alloy with the granularity specification meeting the requirement, composition segregation and inclusion are prevented, and the performance of the titanium alloy is improved.

Description

Technical Field

[0001] This invention belongs to the field of intermediate alloy preparation technology, specifically relating to an apparatus and method for preparing bean-shaped Al-37Sn intermediate alloy. Background Technology

[0002] Titanium alloys are high-performance metallic materials made from titanium as a base, incorporating alloying elements such as aluminum (Al), vanadium (V), tin (Sn), zirconium (Zr), and molybdenum (Mo). Due to their high specific strength (strength-to-density ratio), excellent corrosion resistance, good high-temperature stability, and biocompatibility, they are widely used in aerospace, biomedicine, marine engineering, chemical equipment, and high-end manufacturing. In the aerospace field, titanium alloys are mainly used to manufacture compressor blades and casings for aircraft engines, rocket engine shells, and load-bearing structural components for high-speed aircraft, significantly reducing weight and improving fuel efficiency. In the medical field, titanium alloys, due to their good biocompatibility with human tissue, are widely used in implantable devices such as artificial joints, bone screws, and dental implants. Furthermore, in chemical and marine engineering, titanium alloys, with their excellent resistance to seawater and acid / alkali corrosion, are ideal materials for critical equipment such as heat exchangers and deep-sea exploration equipment.

[0003] However, titanium alloys have poor machinability and are prone to problems such as compositional segregation, hot cracking, and oxidation during smelting and hot working, affecting their mechanical properties and forming quality. Therefore, optimizing the preparation process of titanium alloys, such as using homogenized master alloys to improve the metallurgical quality of titanium alloys, is an important direction in current titanium alloy research, and this method has been widely used in the industrial production of titanium alloys.

[0004] Sn, an important alloying element in titanium alloys, has a certain solid solubility in both α- and β-type titanium alloys. Solid solution strengthening enhances the strength of titanium alloys. In near-α-type titanium alloys (such as Ti-5Al-2.5Sn), Sn refines the α-phase grains, improving overall mechanical properties while maintaining good plasticity and preventing excessive embrittlement. The addition of Sn can slow down grain boundary diffusion and phase coarsening in titanium alloys at high temperatures, improving creep resistance and making it suitable for high-temperature environments such as aero-engine components. Sn-containing titanium alloys (such as Ti-6Al-7Nb) perform excellently in medical implants; the passivation film of Sn enhances the corrosion resistance of titanium alloys in bodily fluid environments. Therefore, almost all titanium alloys requiring high strength, corrosion resistance, excellent overall mechanical properties, and good plasticity both domestically and internationally incorporate appropriate amounts of tin. Titanium alloys of relevant grades are used in the aerospace field for their high strength and fatigue resistance in aircraft structural components and engine parts; in the chemical and marine engineering field for their high corrosion resistance in heat exchangers, pipelines, seawater desalination equipment, etc.; and in the medical field for their excellent biocompatibility and corrosion resistance in implants such as fixation plates and orthopedic screws.

[0005] In titanium alloy production, Sn is typically added as an Al-37Sn master alloy additive, except for special grades of titanium alloys which use dedicated master alloys. During the smelting of traditional Al-37Sn master alloys, due to the significant difference in specific gravity between Al and Sn, compositional segregation occurs in the ingot during the cooling process after smelting, leading to uneven composition in the master alloy product. Furthermore, this master alloy needs to be crushed into chips with a particle size of (0.08~1.0)×(3~12)×(5~15) mm before being uniformly incorporated into the titanium alloy melt. This is usually achieved by first machining the Al-37Sn master alloy ingot and then crushing the chips to the appropriate size. However, the machined Al-37Sn alloy chips have high toughness, and the freshly machined chips lack a dense oxide layer, making direct crushing difficult. Mechanical crushing is energy-intensive and inefficient. The natural oxygen absorption embrittlement of Al-37Sn alloy scrap requires exposure to air for several weeks to several months, which is too long. If heat treatment (such as low-temperature annealing) is used directly for embrittlement, the scrap will stick together, affecting subsequent dispersibility.

[0006] Therefore, in order to solve the segregation problem of Al-37Sn master alloy ingots and the problem of rapid crushing of scrap, it is necessary to provide a new method and apparatus for preparing Al-37Sn master alloy. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides an apparatus and method for preparing bean-shaped Al-37Sn master alloys. The technical problem to be solved by this invention is achieved through the following technical solution: An apparatus for preparing bean-shaped Al-37Sn master alloy includes an induction furnace for melting Al-37Sn master alloy, and further includes: a guide channel, a funnel, a water-cooled copper turntable, a separator, a collection bin, and a screening machine; one end of the guide channel is connected to the outlet of the induction furnace, and the other end is inclined downward above the funnel; the funnel is positioned above the water-cooled copper turntable, and has a hole at the bottom; the water-cooled copper turntable and the separator are both horizontally located in the collection bin, the separator is located in the inner cavity of the rotating shaft in the middle of the water-cooled copper turntable and one end extends upward through the rotating shaft, and there is a certain gap between the periphery of the water-cooled copper turntable and the inner side of the collection bin; the screening machine is located below the outlet of the collection bin.

[0008] Preferably, the inclination angle of the guide channel is 15~30°.

[0009] Preferably, the diameter of the funnel's opening is 2-5 mm.

[0010] Preferably, both the guide channel and the funnel are made of graphite.

[0011] Preferably, the separator is a high-pressure air duct with a high-pressure air nozzle, and the high-pressure air nozzle extends upward through the rotating shaft.

[0012] Another embodiment of the present invention provides a method for preparing a bean-shaped Al-37Sn master alloy, which is carried out using the above-mentioned bean-shaped Al-37Sn master alloy preparation apparatus, including: Step 1: Load Al ingots and Sn ingots into a medium-frequency induction furnace at a mass ratio of 63:37, heat to 750~850℃ under an argon atmosphere, and stir to form a uniform Al-37Sn metal melt. Step 2: The Al-37Sn molten metal flows into the funnel through the guide channel, and the temperature of the outflowing Al-37Sn molten metal is controlled to be maintained at 700~800℃; Step 3: The Al-37Sn molten metal entering the funnel drips through the bottom hole into the rotating water-cooled copper disc and solidifies into several Al-37Sn bean-shaped particles. Step 4: The Al-37Sn bean-shaped particles in the water-cooled copper turntable move towards the edge of the water-cooled copper turntable under the action of the separator, and fall into the collection bin through the gap between the periphery of the water-cooled copper turntable and the inner side of the collection bin, and then fall into the screening machine along the lower outlet of the collection bin. Step 5: The Al-37Sn bean-shaped particles are screened by a screening machine to obtain bean-shaped Al-37Sn intermediate alloy with a diameter of 3~8mm.

[0013] Furthermore, in step 3, the rotational speed of the water-cooled copper turntable is 200~500 rpm.

[0014] Furthermore, the water temperature of the water-cooled copper turntable is 5~25℃.

[0015] The beneficial effects of this invention are: 1. The bean-shaped Al-37Sn master alloy particles obtained by the preparation device of the present invention meet the requirements for use, and the sphericity of the particles is ≥90%. They can be directly added to titanium alloys, effectively solving the problem of difficult crushing, greatly shortening the preparation cycle of Al-37Sn master alloy of the required size for titanium alloys, so that they can be added to the smelting of titanium alloys with more uniform particle size. In addition, the rapid cooling method can effectively prevent the problem of Sn element segregation and inclusion in Al-37Sn master alloys, and improve the performance of titanium alloys. 2. This preparation method allows the Al-37Sn master alloy to solidify rapidly, thereby suppressing the segregation of Sn.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figures 2-5 This is a measurement report of the Sn element content in the bean-shaped Al-37Sn master alloy obtained in Example 2 of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1-Guide channel; 2-Function funnel; 3-Water-cooled copper turntable; 4-Separator; 5-Collection bin; 6-Screening machine; 7-Medium frequency induction furnace; 8-Collection bucket. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, but the implementation of the present invention is not limited thereto. Example

[0020] This embodiment discloses a preparation apparatus for a bean-shaped Al-37Sn master alloy. The preparation apparatus includes an induction furnace for melting Al-37Sn master alloy, and further includes: a guide channel 1, a funnel 2, a water-cooled copper turntable 3, a separator 4, a collection bin 5, and a screening machine 6. One end of the guide channel 1 is connected to the discharge port of the medium-frequency induction furnace 7, and the other end is inclined downward above the funnel 2. The funnel 2 is positioned above the water-cooled copper turntable 3, and the bottom of the funnel 2 has a hole. The water-cooled copper turntable 3 and the separator 4 are both horizontally located within the collection bin 5, and the water-cooled copper turntable 3 can be placed within the collection bin 5. The water-cooled copper turntable 3 rotates, and there is a certain gap between the periphery of the turntable and the inner side of the collection bin 5. This gap allows the Al-37Sn intermediate alloy on the turntable 3 to fall into the collection bin 5 as the turntable 3 rotates. The separator 4 is located in the inner cavity of the rotating shaft in the middle of the water-cooled copper turntable 3, with one end extending upward through the shaft. The motor that drives the rotating shaft to rotate is supported by a fixed plate extending out of the collection bin 5 (not shown in the figure). The screening machine 6 is located below the outlet of the collection bin 5. The bean-shaped Al-37Sn intermediate alloy screened by the screening machine 6 is collected through the collection bucket 8.

[0021] The Al-37Sn master alloy ingot, smelted in a medium-frequency induction furnace, flows into a funnel along a guide channel and then into a rotating water-cooled copper disc 3 for cooling and solidification, forming bean-shaped Al-37Sn master alloy particles. These particles are then moved by a separator to the gap between the water-cooled copper disc and the collection bin, falling into the collection bin and then through the outlet at the bottom of the bin into a screening machine for sieving. The sieved bean-shaped Al-37Sn master alloy particles are collected in a collection bucket 8. The sieved bean-shaped Al-37Sn master alloy particles meet the usage requirements, with a sphericity ≥90%, and can be directly added to titanium alloys. This effectively solves the problem of difficult crushing, significantly shortens the preparation cycle of Al-37Sn master alloy of the required size for titanium alloys, and allows it to be added to the smelting of titanium alloys with the required particle size. Furthermore, the rapid cooling method effectively prevents Sn element segregation and inclusion in the Al-37Sn master alloy, improving the performance of the titanium alloy.

[0022] Preferably, both the guide channel 1 and the funnel 2 are made of graphite. First, graphite has good high-temperature resistance, which can reduce the number of times the guide channel and funnel need to be replaced. Second, the graphite can provide a reducing atmosphere, reducing the oxygen content in the Al-37Sn master alloy. In addition, by selecting this combination of graphite materials, it is possible to avoid the Al-37Sn melt flowing out of the medium-frequency induction furnace from being mixed with other impurity elements, thus preventing secondary pollution.

[0023] Furthermore, the inclination angle of the guide channel 1 is 15~30°. By selecting this angle, the Al-37Sn melt flowing out of the medium frequency induction furnace can maintain a suitable flow rate, and finally form a suitable particle size through cooling.

[0024] Furthermore, the diameter of the funnel 2 is 2-5 mm, and the rotation speed of the water-cooled copper turntable 3 is 200-500 rpm, so as to basically ensure that the Al-37Sn metal melt flowing out of the funnel can form the required particle size after cooling in the water-cooled copper turntable.

[0025] It should be noted that the water-cooled copper turntable 3 preferably adopts the utility model patent "A condensing turntable for an aluminum bean granulator CN223171924U" previously applied for by the applicant, and the screening machine 6 adopts existing technology.

[0026] Furthermore, the separator 4 is a high-pressure air pipe with a high-pressure air nozzle, and the high-pressure air nozzle extends upward through the rotating shaft. In this embodiment of the invention, the rotating shaft that drives the water-cooled copper turntable 3 to rotate is transmitted to the motor shaft through a turntable bearing (existing technology, not shown in the figure), and the rotating shaft is a hollow shaft. The high-pressure air pipe extends into the hollow shaft and the high-pressure air nozzle extends upward through the rotating shaft. The high-pressure air pipe and the high-pressure air nozzle do not rotate with the water-cooled copper turntable 3. The solidified bean-shaped Al-37Sn intermediate alloy on the water-cooled copper turntable is blown by the high-pressure air nozzle into the gap between the water-cooled copper turntable and the collection bin, and then falls into the collection bin 5, which is quick, convenient and simple. Example

[0027] This invention discloses a method for preparing bean-shaped Al-37Sn master alloy, which is carried out using the bean-shaped Al-37Sn master alloy preparation apparatus described in Example 1, and specifically includes the following steps: Step 1: Load Al ingots and Sn ingots into a medium-frequency induction furnace at a mass ratio of 63:37, heat to 750~850℃ under an argon atmosphere, and stir to form a uniform Al-37Sn metal melt. Step 2: The Al-37Sn molten metal flows into the funnel through the guide channel, and the temperature of the outflowing Al-37Sn molten metal is controlled to be maintained at 700~800℃. Maintaining this temperature is beneficial to the dripping process in the funnel. Within this temperature range, the fluidity of the alloy liquid is moderate. Below this temperature, the fluidity decreases, the liquid dripping into the funnel is not smooth, and it is easy to have problems such as not flowing, solidification, and blockage. Above this temperature range, the fluidity of the alloy liquid is too strong, and it will become strip-shaped and cannot be formed into bean-shaped pieces.

[0028] Step 3: The Al-37Sn molten metal entering the funnel drips through the bottom hole into the rotating water-cooled copper disc and solidifies into several Al-37Sn bean-shaped particles. The water-cooled copper turntable rotates at 200-500 rpm. If the rotation speed is too high, the alloy liquid will deform upon contact with the turntable. If the rotation speed is too low, the particles will not be able to form a bean shape. In addition, the diameter of the water-cooled copper turntable is 2.0-2.8 m. This rotation speed ensures that the solidified bean-shaped particles will not fly out along the gap between the water-cooled copper turntable and the collection bin.

[0029] The temperature of the outflowing Al-37Sn molten metal is controlled by the heating power of the medium-frequency induction furnace. At the same time, the diameter of the funnel opening and the rotation speed and diameter of the water-cooled copper turntable are controlled. Through these conditions, the final bean-shaped Al-37Sn master alloy basically meets the required particle size.

[0030] In addition, the water temperature of the water-cooled copper turntable is 5~25℃, which means that room temperature water can meet the cooling requirements of Al-37Sn master alloy without the need for additional cost to achieve cooling.

[0031] Step 4: The Al-37Sn bean-shaped particles in the water-cooled copper turntable move towards the edge of the water-cooled copper turntable under the action of the separator, and fall into the collection bin through the gap between the periphery of the water-cooled copper turntable and the inner side of the collection bin, and then fall into the screening machine along the lower outlet of the collection bin. Step 5: The Al-37Sn bean-shaped particles are screened by a screening machine to obtain bean-shaped Al-37Sn intermediate alloy with uniform particle size and diameter of 3~8mm, and collected through collection bucket 8.

[0032] Four equal-volume samples were taken from the center and three symmetrical points around each barrel in the same batch. The Sn element content of the four equal-volume samples was determined, and the results are as follows: Figures 2-5 As can be seen, the Sn element composition is uniform and basically consistent with the target composition, indicating that the bean-shaped Al-37Sn master alloy obtained by this preparation method has a uniform composition and is basically consistent with the target composition, and the Sn element has not segregated.

[0033] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. An apparatus for preparing a bean-shaped Al-37Sn master alloy, comprising an induction furnace for melting the Al-37Sn master alloy, characterized in that, Also includes: The system includes a guide channel, a funnel, a water-cooled copper turntable, a separator, a collection bin, and a screening machine. One end of the guide channel is connected to the outlet of the induction furnace, and the other end is inclined downward above the funnel. The funnel is located above the water-cooled copper turntable and has a hole at the bottom. The water-cooled copper turntable and the separator are both horizontally located inside the collection bin. The separator is located in the inner cavity of the rotating shaft in the middle of the water-cooled copper turntable and one end extends upward through the rotating shaft. There is a certain gap between the periphery of the water-cooled copper turntable and the inner side of the collection bin. The screening machine is located below the outlet of the collection bin.

2. The apparatus for preparing bean-shaped Al-37Sn master alloy according to claim 1, characterized in that, The inclination angle of the guide channel is 15~30°.

3. The apparatus for preparing bean-shaped Al-37Sn master alloy according to claim 1, characterized in that, The diameter of the funnel's opening is 2-5 mm.

4. The apparatus for preparing bean-shaped Al-37Sn master alloy according to claim 1, characterized in that, Both the guide channel and the funnel are made of graphite.

5. The apparatus for preparing bean-shaped Al-37Sn master alloy according to claim 1, characterized in that, The separator is a high-pressure air duct with a high-pressure air nozzle, and the high-pressure air nozzle extends upward through the rotating shaft.

6. A method for preparing a bean-shaped Al-37Sn master alloy, characterized in that, The preparation is carried out using the bean-shaped Al-37Sn master alloy preparation apparatus according to claims 1-5, comprising: Step 1: Load Al ingots and Sn ingots into a medium-frequency induction furnace at a mass ratio of 63:37, heat to 750~850℃ under an argon atmosphere, and stir to form a uniform Al-37Sn metal melt. Step 2: The Al-37Sn molten metal flows into the funnel through the guide channel, and the temperature of the outflowing Al-37Sn molten metal is controlled to be maintained at 700~800℃; Step 3: The Al-37Sn molten metal entering the funnel drips through the bottom hole into the rotating water-cooled copper disc and solidifies into several Al-37Sn bean-shaped particles. Step 4: The Al-37Sn bean-shaped particles in the water-cooled copper turntable move towards the edge of the water-cooled copper turntable under the action of the separator, and fall into the collection bin through the gap between the periphery of the water-cooled copper turntable and the inner side of the collection bin, and then fall into the screening machine along the lower outlet of the collection bin. Step 5: The Al-37Sn bean-shaped particles are screened by a screening machine to obtain bean-shaped Al-37Sn intermediate alloy with a diameter of 3~8mm.

7. The method for preparing bean-shaped Al-37Sn master alloy according to claim 5, characterized in that, In step 3, the rotation speed of the water-cooled copper turntable is 200~500 rpm.

8. The method for preparing bean-shaped Al-37Sn master alloy according to claim 5, characterized in that, In step 3, the water temperature of the water-cooled copper turntable is 5~25℃.

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