Heat-treatment-free die-casting alloy material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of alloy material casting, and discloses a heat-treatment-free die-casting alloy material and a preparation method and application thereof, and the heat-treatment-free die-casting alloy material comprises various rare earth elements and aluminum. According to the alloy material, the eutectic reaction of Si, Mg and Al is utilized, so that the alloy has good fluidity and casting formability in the solidification process, by means of the action of high-melting-point transition metal elements Mn, Cr, V, Mo and Zr, grains are refined, the thermal stability of the alloy is improved, the material has good room-temperature performance, meanwhile, the material can serve for a long time at a certain temperature, and the service life of the material is prolonged. The modification and refinement effects of rare earth elements, Ga, In and Al-Ti-B on crystal grains and eutectic structures are comprehensively utilized, the microstructure of the alloy is improved, the material has high strength and plasticity in the die-casting state, subsequent heat treatment is not needed, the procedures of deformation, correction and the like are reduced, the rejection rate is reduced, and the production period is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of alloy material casting technology, in particular to an as-cast alloy material and a preparation method and application thereof. BACKGROUND

[0002] In order to reduce fuel consumption and environmental load, the lightweight of the automobile industry is the main development trend. Among them, the aluminum alloy of automobile parts and its body is an important way to achieve the weight reduction, cost reduction, energy saving and emission reduction of the automobile industry. There are a large number of automobile parts with complex shape and large wall thickness change in automobiles. The traditional process is to process and manufacture by stamping, forging, extrusion and other means on steel or aluminum materials. Compared with this, high-pressure die casting can obtain aluminum alloy workpieces close to the final shape and size, reduce subsequent processing procedures, and effectively reduce the manufacturing cost. However, the existing die-casting aluminum alloy materials for high-pressure die casting have low strength in the casting state, and need to be heat treated to improve their comprehensive performance to meet the performance requirements of the automobile parts. Generally, aluminum alloy parts need to go through solid solution treatment, artificial aging and other heat treatment processes. Among them, the solid solution treatment is a process of heating the workpiece to a high temperature in a high-temperature furnace and holding for a certain time, and then taking out and water cooling to room temperature; the artificial aging is to heat the workpiece after solid solution treatment at a temperature of 150-200 DEG C for 4-12 hours to improve the strength of the aluminum alloy material and obtain better mechanical properties. The aluminum alloy die casting with complex shape after high-pressure die casting is prone to strong deformation after solid solution treatment, and needs to be corrected in shape and size. The subsequent artificial aging time is long, the waste rate of the die-casting aluminum alloy workpiece after heat treatment is high, the production cycle is long, and the cost is high. In view of this situation, it is difficult to judge whether the aluminum alloy automobile parts produced by aluminum alloy die casting and heat treatment process have the effect of reducing cost compared with the automobile parts produced by traditional stamping and welding process. The die-casting aluminum alloy materials commonly used in China at present are Al-Si series aluminum alloys, and the commonly used grades are ADC12, A380, 46500, etc. This kind of die-casting aluminum alloy has a certain strength in the as-cast state without heat treatment, but the plasticity is generally poor, which leads to poor dynamic mechanical properties, such as low impact toughness and fracture toughness, etc., and it is difficult to meet the development requirements of the automobile industry on the comprehensive performance of as-cast aluminum alloy die casting.

[0003] Therefore, it is of great practical significance to provide an as-cast die-casting aluminum alloy material without heat treatment, which has high strength and toughness and excellent die-casting forming property, to meet the development needs of the integrated forming of automobile parts with complex shape. SUMMARY

[0004] In view of this, the present application proposes a heat treatment-free die casting alloy material and its preparation method and application, aiming to solve at least one of the above background technical problems.

[0005] The present application proposes a heat treatment-free die casting alloy material, comprising the following components by mass fraction: Si: 1.0~4.0%, Mg: 1.5~8.5%, Cu: 0.03~3.0%, Zn: 0.03~3.0%, Fe≤0.2%, Mn: 0.05~0.8%, Cr: 0.05~0.6%, Ti: 0.03~0.3%, V: 0.01~0.3%, Mo: 0.01~0.3%, Zr: 0.03~0.3%, In: 0.001~0.05%, Ga: 0.001~0.05%, B: 0.005~0.06%, Be: 0.0003~0.002%, Sc: 0.03~0.4%, Gd: 0.03~0.4%, Dy: 0.03~0.4%, the balance being aluminum.

[0006] Preferably, the alloy material is obtained from aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy and aluminum dysprosium intermediate alloy; The gallium content in the gallium-indium alloy is 30~60%, and the indium content is 40~70%; The contents of scandium, gadolinium and dysprosium in the aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy and aluminum dysprosium intermediate alloy are 1.95~2.10%, 9.5~10.5% and 4.8~5.2% respectively; The mass ratio of scandium, gadolinium and dysprosium in the alloy material is (1~2):(2~4):(1~5).

[0007] The present application also provides a preparation method of the heat treatment-free die casting alloy material described in the above technical solution, comprising the following steps: Step (1), preparing raw materials: aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, aluminum dysprosium intermediate alloy; Step (2), loading the first batch of raw materials into a smelting furnace to heat, melt and heat preserve for first-stage smelting, the first batch of raw materials including aluminum ingot, metallic silicon, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy and aluminum zirconium intermediate alloy, and mechanical stirring is applied to the melt during smelting; The first batch of raw materials is melted, and then a second batch of raw materials is added for a second stage of melting, the second batch of raw materials including aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, and aluminum dysprosium intermediate alloy, and mechanical stirring is applied to the melt during the melting; The second batch of raw materials is melted, and then a third batch of raw materials is added for a third stage of melting, the third batch of raw materials including magnesium ingot and gallium-indium alloy, and mechanical stirring is applied to the melt during the melting, to obtain an aluminum alloy melt; Step (3), the aluminum alloy melt obtained in step (2) is subjected to primary refining treatment, and then the slag in the furnace is removed, and after the refining is completed, sampling analysis is performed again, if the composition is still within the expected index range, it is not necessary to process and enter the next process; if the composition deviates, composition adjustment is performed, and sampling analysis is performed again, and secondary refining and slag removal treatment are performed until all elements reach the expected index, and then the next process can be entered; Step (4), the aluminum alloy melt is discharged from the bottom of the furnace for casting, and when the aluminum alloy melt enters the runner, aluminum titanium boron intermediate alloy wire is added for grain refinement treatment, and after the aluminum alloy melt is subjected to double-stage filtration treatment, it is introduced into an automatic casting machine for casting, to obtain the heat treatment-free die casting alloy material.

[0008] Preferably, the temperature of the first stage of melting is 760-800 DEG C, the temperature of the second stage of melting is 740-780 DEG C, and the temperature of the third stage of melting is 720-760 DEG C.

[0009] Preferably, the mixed gas used in the primary refining treatment is prepared by mixing high-purity argon, high-purity nitrogen and high-purity chlorine, wherein the proportion of high-purity argon is 28%, the proportion of high-purity nitrogen is 70%, and the proportion of high-purity chlorine is 2%, and the primary refining treatment time is 30-60 minutes; the temperature and gas of the secondary refining treatment are the same as those of the primary refining treatment, and the secondary refining treatment time is 15-30 minutes.

[0010] Preferably, the first-stage filter plate in the double-stage filtration is 60 mesh, and the second-stage filter plate is 80 mesh; during the casting process, the temperature of the aluminum alloy melt above the mold plate is maintained at 640-720 DEG C.

[0011] The application also provides application of the heat treatment-free die casting alloy material in die casting products.

[0012] The application also provides a preparation method of a die casting product, including the following steps: The heat treatment-free die casting alloy material is subjected to remelting and stirring to obtain an alloy melt; The alloy melt is subjected to refining treatment, and then slag removal and standing heat preservation treatment are performed, and finally the alloy melt is subjected to die casting forming to obtain the die casting product.

[0013] Preferably, the heat treatment free die casting alloy material is prepared by the method of claim 3; the temperature of the remelting is 720-760℃; the temperature of the refining treatment is 710-730℃, and the time is 10-30 minutes; the mixed gas used in the refining treatment is made of high-purity argon, high-purity nitrogen and high-purity chlorine, wherein the proportion of high-purity argon is 28%, the proportion of high-purity nitrogen is 70%, and the proportion of high-purity chlorine is 2%; and the temperature of the holding treatment is 680-720℃.

[0014] Preferably, the die casting is high pressure die casting, and the first stage injection speed is 0.1-0.5m / s, the second stage injection speed is 2-5m / s, the third stage injection speed is 5-20m / s, the die casting pressure is 50-100MPa, and the holding time is 30-90 seconds.

[0015] Compared with the prior art, the present application has the following beneficial effects: (1) The alloy material of the present application utilizes the eutectic reaction of Si, Mg and Al, so that the alloy has good fluidity and castability during solidification, and is suitable for die casting production of complex shaped workpieces, meeting the needs of the automobile industry for integrated forming of complex parts.

[0016] (2) The present application utilizes the effects of high melting point transition metal elements Mn, Cr, V, Mo and Zr, not only refining the grains, but also improving the thermal stability of the alloy, so that the material can serve for a long time at a certain temperature while having good room temperature performance, expanding the application scenarios of the material.

[0017] (3) The present application comprehensively utilizes the modification and refinement effects of rare earth elements, Ga, In elements and Al-Ti-B on grain and eutectic structure, improves the microstructure of the alloy, so that the material has high strength and plasticity in the die casting state, without subsequent heat treatment, reducing the deformation, correction and other processes, reducing the waste rate, shortening the production cycle and reducing the production cost. The material prepared by the present application has excellent performance, and can be widely applied to complex die castings such as automobile integrated frames, promoting the lightweight development of the automobile industry, and having good economic and social benefits. DETAILED DESCRIPTION

[0018] Now, various exemplary embodiments of the present application will be described in detail, which should not be considered as limiting the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application. It should be understood that the terms described in the present application are only for describing the particular embodiments, and are not used to limit the present application.

[0019] In addition, for numerical ranges of the present application, it is intended that every intermediate value of the upper and lower limits of the range in addition to the upper and lower limits are specifically included. Each smaller range between any stated value or stated range, as well as each value and sub-range within all stated ranges and sub-ranges are also included within the scope of the present application. The upper and lower limits of these smaller ranges can independently be included or excluded in the ranges.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned herein are incorporated by reference to disclose and describe in full the methods and / or materials which are described therein. In the case of conflict between the present specification and any document incorporated herein by reference, the present specification will control.

[0021] Various modifications and changes can be made to the specific embodiments of the present application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples that follow. The description and examples are illustrative of the application and are not intended to limit the scope of the application in any way.

[0022] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having" or the like are open-ended expressions that are intended to denote the presence of stated features, elements, integers, steps or the like, but do not preclude the presence or addition of one or more other features, elements, integers, steps, acts, objects, binaries or the like.

[0023] The present application provides a heat treatment-free die casting alloy material, comprising the following components by mass fraction: Si: 1.0-4.0%, Mg: 1.5-8.5%, Cu: 0.03-3.0%, Zn: 0.03-3.0%, Fe≤0.2%, Mn: 0.05-0.8%, Cr: 0.05-0.6%, Ti: 0.03-0.3%, V: 0.01-0.3%, Mo: 0.01-0.3%, Zr: 0.03-0.3%, In: 0.001-0.05%, Ga: 0.001-0.05%, B: 0.005-0.06%, Be: 0.0003-0.002%, Sc: 0.03-0.4%, Gd: 0.03-0.4%, Dy: 0.03-0.4%, and the balance being aluminum.

[0024] In the present application, the inevitable single impurity elements in the heat treatment-free die casting alloy material are ≤0.03%, and the total amount of impurity elements is ≤0.15%.

[0025] The rare earth elements Sc, Gd and Dy have the function of "solid hydrogen" in the aluminum alloy, which mainly shows in two aspects: one is that the rare earth elements are more active and have greater affinity with H, and can generate stable compounds with hydrogen to convert free hydrogen into combined hydrogen; the other is that some intermetallic compounds containing rare earth can chemically adsorb part of hydrogen to convert free hydrogen into adsorbed hydrogen. The above two functions of the rare earth elements can effectively reduce the content of free hydrogen in the aluminum alloy melt, thereby inhibiting the precipitation of hydrogen and the formation of hydrogen gas during the solidification process, reducing the possibility of hydrogen gas escaping in the as-cast state, and reducing the porosity of the alloy in the as-cast state.

[0026] In addition, the rare earth elements can react with the Al2O3 inclusions in the aluminum alloy melt to form certain RE-Al-O multi-phase substances, which have a higher density than the aluminum melt and can sink to the bottom of the crucible to realize the separation of inclusions. The rare earth elements can form a class of intermetallic compounds such as Al3Sc, Al3Gd and Al3Dy in the aluminum alloy system, which have the characteristics of high melting point and high thermal stability. These intermetallic compounds can act as nucleation cores of α-Al during the solidification process of the aluminum alloy, and promote the nucleation rate of α-Al grains. The rare earth elements will transfer from the solid phase to the liquid phase during the solidification process of the alloy, and enrich on the surface of the Mg2Si phase generated by the eutectic reaction, change the surface energy state of the Mg2Si phase, and reduce its tendency to preferentially grow, thereby improving and refining the morphology of the Mg2Si phase generated by the eutectic reaction, and finally exhibiting modification effect on the eutectic structure. The rare earth elements can effectively change the crystallization kinetics of the Fe-rich phase during the solidification process of the aluminum alloy, thereby changing it from needle-like to fishbone-like, Chinese character-like or short rod-like, and improving the plasticity of the alloy.

[0027] Ga and In elements can enrich on the surface of the Mg2Si phase during the solidification process, change its surface energy state, change the preferential orientation state of the Mg2Si phase crystallization, and play a modification role. Cu and Zn elements have a high solid solubility in α-Al, which can produce obvious solid solution strengthening effect and improve the strength of the alloy.

[0028] The aluminum alloy material of the present application has a high content of Mg, and the oxide film produced by Mg element is not dense, which cannot protect the surface of the melt, so a small amount of Be element is added during the smelting process of the aluminum alloy with high Mg content to supplement the cracks of the MgO film, so that a relatively dense oxide film is formed on the surface of the aluminum alloy melt to reduce the burning loss of Mg element in the aluminum alloy melt and control the hydrogen content of the melt.

[0029] Mn, Cr, V, Mo, Zr, etc. all belong to transition metal elements, and their roles in the present application mainly fall into two categories. The first category is Mn and Cr elements. Mn elements have certain solid solution strengthening effect on one hand; on the other hand, Mn and Cr elements can change the morphology of Fe-rich phase and reduce the size of Fe-rich phase, thereby improving the plasticity of the aluminum alloy material; in the third aspect, the fine intermediate phase formed by Mn, Cr elements, Si and Fe elements has a high melting point, and the diffusion coefficient of Mn and Cr in the aluminum alloy matrix can still be maintained at a low level under certain high temperature conditions, thereby improving the high temperature resistance of the aluminum alloy. V, Mo and Zr elements can form complex intermediate phases with Al elements, and they are the first to precipitate during the casting and solidification process, thereby providing crystal nuclei for the formation of aluminum alloy grains and having the effect of refining the aluminum alloy grains; at the same time, the complex intermediate phases formed by V, Mo and Zr with Al have a high melting point and a low diffusion coefficient in the aluminum alloy, so that the formed intermediate phases have high thermal stability, thereby improving the high temperature resistance of the aluminum alloy material.

[0030] Ti and B elements are added simultaneously by means of aluminum-titanium-boron intermediate alloy. The aluminum-titanium-boron is a commonly used grain refiner for aluminum alloy, which is added in the flow tank after tapping and before casting, so as to further refine the grain size of the aluminum alloy.

[0031] In the present application, the alloy material is preferably obtained from aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy and aluminum dysprosium intermediate alloy. The content of gallium in the gallium-indium alloy is preferably 30-60%, and the content of indium is preferably 40-70%; The contents of scandium, gadolinium and dysprosium in the aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy and aluminum dysprosium intermediate alloy are respectively preferably 1.95-2.10%, 9.5-10.5% and 4.8-5.2%; The mass ratio of scandium, gadolinium and dysprosium in the alloy material is preferably (1-2):(2-4):(1-5).

[0032] The present application also provides a preparation method of the heat treatment-free die casting alloy material according to the above technical solution, which comprises the following steps: Step (1), preparing raw materials: aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy and aluminum dysprosium intermediate alloy. Step (2), the first batch of raw materials is loaded into a smelting furnace to be heated, melted and kept for the first stage smelting, the first batch of raw materials includes aluminum ingot, metallic silicon, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, and mechanical stirring is applied to the melt during the smelting; After the first batch of raw materials is melted, the second batch of raw materials is added for the second stage smelting, the second batch of raw materials includes aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, aluminum dysprosium intermediate alloy, and mechanical stirring is applied to the melt during the smelting; After the second batch of raw materials is melted, the third batch of raw materials is added for the third stage smelting, the third batch of raw materials includes magnesium ingot and gallium-indium alloy, and mechanical stirring is applied to the melt during the smelting, so as to obtain an aluminum alloy melt; Step (3), the aluminum alloy melt obtained in step (2) is subjected to primary refining treatment, then the slag in the furnace is removed, and after the refining is completed, sampling analysis is performed again, if the composition is still within the expected index range, it is not necessary to be processed into the next process; if the composition deviates, component adjustment is performed, and sampling analysis is performed again, and secondary refining and slag removal treatment are performed until all elements reach the expected index, so as to enter the next process; Step (4), the aluminum alloy melt is discharged from the bottom of the smelting furnace for casting, aluminum titanium boron intermediate alloy wire is added to the aluminum alloy melt when the aluminum alloy melt enters the runner for grain refinement treatment, and the aluminum alloy melt is subjected to double-stage filtration treatment and then enters an automatic casting machine for casting, so as to obtain the heat treatment-free die casting alloy material.

[0033] In the present application, the temperature of the first stage smelting is preferably 760-800℃, the temperature of the second stage smelting is preferably 740-780℃, and the temperature of the third stage smelting is preferably 720-760℃.

[0034] In the present application, the mixed gas used in the primary refining treatment is preferably made of high-purity argon, high-purity nitrogen and high-purity chlorine, wherein the proportion of high-purity argon is 28%, the proportion of high-purity nitrogen is 70%, and the proportion of high-purity chlorine is 2%, and the primary refining treatment time is 30-60 minutes; the temperature and gas of the secondary refining treatment are the same as those of the primary refining treatment, and the secondary refining treatment time is preferably 15-30 minutes.

[0035] In the present application, the first-stage filter plate in the double-stage filtration is preferably 60 mesh, and the second-stage filter plate is preferably 80 mesh; during the casting process, the temperature of the aluminum alloy melt above the mold plate is preferably maintained at 640-720℃.

[0036] The present application also provides the application of the heat treatment-free die casting alloy material in the die casting product.

[0037] The application further provides a preparation method of the die casting. The heat treatment-free die casting alloy material is remelted and stirred to obtain an alloy melt; The alloy melt is subjected to refining treatment, then is subjected to slagging and standing heat preservation treatment, and finally is subjected to die casting forming to obtain the die casting.

[0038] In the application, the heat treatment-free die casting alloy material is the heat treatment-free die casting alloy material prepared in claim 3; the temperature of the remelting is preferably 720-760 DEG C; the temperature of the refining treatment is preferably 710-730 DEG C, and the time is preferably 10-30 minutes; the mixed gas used in the refining treatment is preferably mixed by high-purity argon, high-purity nitrogen and high-purity chlorine, wherein the proportion of the high-purity argon is 28%, the proportion of the high-purity nitrogen is 70%, and the proportion of the high-purity chlorine is 2%; and the temperature of the heat preservation treatment is preferably 680-720 DEG C.

[0039] In the application, the die casting forming preferably adopts high-pressure die casting, and in the die casting process, the first-stage injection speed is preferably 0.1-0.5 m / s, the second-stage injection speed is preferably 2-5 m / s, the third-stage injection speed is preferably 5-20 m / s, the die casting pressure is preferably 50-100 MPa, and the pressure holding time is preferably 30-90 seconds.

[0040] The purity of the high-purity argon, the high-purity nitrogen and the high-purity chlorine in the application is all 99.99%.

[0041] Example 1 (1) Prepare raw materials: Si: 1.6%, Mg: 4.1%, Cu: 0.62%, Zn: 0.43%, Fe: 0.13%, Mn: 0.30%, Cr: 0.25%, Ti: 0.08%, V: 0.11%, Mo: 0.10%, Zr: 0.10%, In: 0.008%, Ga: 0.007%, B: 0.01%, Be: 0.0010%, Sc: 0.06%, Gd: 0.12%, Dy: 0.16%, other unavoidable single impurity elements ≤0.03%, total amount of impurity elements ≤0.15%, and the balance is aluminum. Among them, the proportion of Ga element in the gallium-indium alloy is 46.7%, the proportion of In element is about 53.3%, and the ratio of Sc, Gd and Dy elements is 1.5:3:4.

[0042] According to the required raw materials for the composition of the heat treatment-free die casting aluminum alloy material, the raw materials include aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, and aluminum dysprosium intermediate alloy. (2) Part of the raw materials are loaded into the smelting furnace to be heated and melted, and the first stage smelting is carried out at 780℃. The first batch of raw materials loaded into the furnace include aluminum ingot, metallic silicon, electrolytic copper, zinc ingot, aluminum manganese master alloy, aluminum chromium master alloy, aluminum vanadium master alloy, aluminum molybdenum master alloy, and aluminum zirconium master alloy. Mechanical stirring is applied to the melt during the holding and smelting process to uniformly disperse the alloy elements. After the above-mentioned furnace charge is melted and uniformly stirred, the temperature is reduced to 760℃, and then aluminum beryllium master alloy, aluminum scandium master alloy, aluminum gadolinium master alloy, and aluminum dysprosium master alloy are added. After complete melting, the temperature is held at 760℃ for holding and smelting, and mechanical stirring is applied to uniformly disperse the alloy elements. After the above-mentioned furnace charge is melted and uniformly stirred, the temperature is reduced to 740℃, and then magnesium ingot and gallium-indium alloy are added. After complete melting, the temperature is held at 720℃-740℃ for holding and smelting, and mechanical stirring is applied to uniformly disperse the alloy elements. Then, a small amount of sample is taken from the high-temperature aluminum alloy melt after solidification for chemical composition analysis. If the composition deviates, the composition is adjusted and the sample is analyzed again until all elements reach the expected index. (3) The aluminum alloy melt in the furnace is treated with a mixed gas composed of 99.99% high-purity argon gas at 28%, 99.99% high-purity nitrogen gas at 70%, and 99.99% high-purity chlorine gas at 2% for primary refining. The treatment time is 50 minutes. Then the slag in the furnace is removed. After refining, the sample is analyzed again. If the composition is still within the expected index range, it does not need to be treated and can proceed to the next process. If the composition deviates, the composition is adjusted and the sample is analyzed again for secondary refining and slag removal until all elements reach the expected index before proceeding to the next process. (4) When the temperature of the aluminum alloy melt in the smelting furnace reaches 700-720℃, the aluminum alloy melt is discharged from the bottom of the smelting furnace for casting. When the aluminum alloy melt enters the flow channel, aluminum titanium boron master alloy wire is added for grain refinement treatment. The aluminum alloy melt is subjected to double-stage filtration treatment with a first-stage filter plate of 60 mesh and a second-stage filter plate of 80 mesh, and then enters the automatic casting machine for casting to obtain heat treatment-free die casting aluminum alloy ingot. The temperature of the aluminum alloy melt above the casting mold is 695℃, and the heat treatment-free die casting alloy material is obtained, with each alloy weighing about 5 kg.

[0043] The high-pressure die casting process of the die casting is as follows: Step (1) The heat treatment-free die casting aluminum alloy ingot prepared is remelted at 740℃ and stirred to uniformly disperse the alloy elements. Step (2) When the temperature of the aluminum alloy melt is reduced to 720℃, the alloy melt is treated with a mixed gas composed of 99.99% high-purity argon gas at 28%, 99.99% high-purity nitrogen gas at 70%, and 99.99% high-purity chlorine gas at 2% for refining. The refining lasts for 15 minutes, then the slag is removed, and the temperature is controlled at 685℃ for holding, preparing for high-pressure die casting. The aluminum alloy melt in the smelting furnace is required to be maintained at 680-690℃ during the entire high-pressure die casting process. Step (3) uses an automatic soup mechanical arm to transfer a certain amount of alloy melt from the melting furnace to the cold chamber die casting machine cylinder, and carries out high pressure die casting. The first stage injection speed is 0.25 m / s, the second stage injection speed is 2.5 m / s, the third stage injection speed is 8.0 m / s, the die casting pressure is 85 MPa, and after 45 seconds of pressure maintaining, the workpiece is taken out from the die casting machine mold by using a mechanical hand, and the die casting part is obtained after cooling.

[0044] Example 2 (1) Prepare raw materials: Si: 3.1%, Mg: 4.1%, Cu: 1.3%, Zn: 0.83%, Fe: 0.10%, Mn: 0.36%, Cr: 0.17%, Ti: 0.10%, V: 0.16%, Mo: 0.20%, Zr: 0.13%, In: 0.01%, Ga: 0.008%, B: 0.02%, Be: 0.0006%, Sc: 0.11%, Gd: 0.22%, Dy: 0.15%, other unavoidable single impurity elements ≤0.03%, total amount of impurity elements ≤0.15%, the balance is aluminum. Among them, the Ga element in the gallium-indium alloy accounts for 45.5%, the In element accounts for about 55.5%, and the ratio of Sc, Gd and Dy elements is 1.5:3:4.

[0045] According to the composition of the heat treatment-free die casting aluminum alloy material required by the raw materials, the raw materials are: aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, aluminum dysprosium intermediate alloy; (2) Part of the raw materials are loaded into the melting furnace for heating and melting, and the first stage melting is carried out at 780℃. The first batch of raw materials loaded into the furnace are: aluminum ingot, metallic silicon, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, and aluminum zirconium intermediate alloy. During the heat preservation and melting period, mechanical stirring is applied to the melt to uniformly disperse the alloy elements. After the above furnace charge is melted and uniformly stirred, it is cooled to 760℃, and then aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, and aluminum dysprosium intermediate alloy are added. After complete melting, heat preservation and melting are carried out at 760℃, and mechanical stirring is carried out to uniformly disperse the alloy elements. After the above furnace charge is melted and uniformly stirred, it is cooled to 740℃, and then magnesium ingot and gallium-indium alloy are added. After complete melting, heat preservation and melting are carried out at 720℃-740℃, and mechanical stirring is carried out to uniformly disperse the alloy elements. Then, a small amount of sample is taken from the high-temperature aluminum alloy melt for solidification and chemical composition analysis. If the composition is deviated, the composition is adjusted and sampled again until all elements reach the expected index. (3) using a mixture of 99.99% high-purity argon 28%, 99.99% high-purity nitrogen 70%, 99.99% high-purity chlorine 2% to the aluminum alloy melt in the furnace for refining treatment, the treatment time is 50 minutes, then the slag in the furnace is taken out, after refining, sampling analysis, if the composition is still in the expected range, no need to process into the next process; if the composition deviation is adjusted and sampled again, and the second refining and slag treatment is carried out, until all elements reach the expected index can enter the next process; (4) when the aluminum alloy melt in the smelting furnace reaches 700~720℃, the aluminum alloy melt is discharged from the bottom of the smelting furnace for casting, when the aluminum alloy melt enters the runner, aluminum titanium boron master alloy wire is added for grain refinement treatment, the aluminum alloy melt is treated by double-stage filtration of the first stage filter plate of 60 mesh and the second stage filter plate of 80 mesh, and then enters the automatic casting machine for casting to obtain heat treatment-free die casting aluminum alloy ingot, the temperature of the aluminum alloy melt above the casting mold is 695℃, and the heat treatment-free die casting alloy material is obtained, and the weight of each alloy is about 5kg.

[0046] The high-pressure die casting process of the die casting is as follows.

[0047] Step (1) remelt the heat treatment-free die casting aluminum alloy ingot prepared at 735℃ and stir to disperse the alloy elements uniformly; Step (2) when the temperature of the aluminum alloy melt decreases to 720℃, the alloy melt is refined using a mixture of 99.99% high-purity argon 28%, 99.99% high-purity nitrogen 70%, 99.99% high-purity chlorine 2%, the refining lasts for 20 minutes, then the slag is removed, and the temperature is controlled at 700℃ for heat preservation, preparing for high-pressure die casting, the aluminum alloy melt in the smelting furnace is required to be kept at 700℃ during the whole high-pressure die casting process; Step (3) a certain amount of alloy melt is transferred from the melting furnace to the cold chamber die casting machine cylinder by using an automatic soup taking mechanical arm, high-pressure die casting is carried out, the first stage injection speed is 0.30m / s, the second stage injection speed is 3.0m / s, the third stage injection speed is 10.0m / s, the die casting pressure is 75MPa, and the workpiece is taken out from the die casting machine mold by using a mechanical hand after 80 seconds of pressure holding, and the die casting is obtained after cooling.

[0048] Example 3 (1) Preparation of raw materials: Si: 2.8%, Mg: 7.2%, Cu: 0.65%, Zn: 1.24%, Fe: 0.09%, Mn: 0.33%, Cr: 0.21%, Ti: 0.12%, V: 0.23%, Mo: 0.19%, Zr: 0.16%, In: 0.02%, Ga: 0.03%, B: 0.024%, Be: 0.0014%, Sc: 0.13%, Gd: 0.23%, Dy: 0.07%, other unavoidable single impurity elements ≤0.03%, total amount of impurity elements ≤0.15%, the balance is aluminum. Among them, the Ga element accounts for 60% in the gallium-indium alloy, and the In element accounts for about 40%; the ratio of Sc, Gd and Dy elements is 1.8:3.3:1.

[0049] According to the required raw materials for the composition configuration of the heat treatment-free die casting aluminum alloy material, the raw materials are: aluminum ingot, metallic silicon, magnesium ingot, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum titanium boron intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, aluminum zirconium intermediate alloy, gallium-indium alloy, aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, and aluminum dysprosium intermediate alloy; (2) Part of the raw materials are loaded into the melting furnace for heating and melting, and the first stage melting is carried out at 790℃. The first batch of raw materials loaded into the furnace are: aluminum ingot, metallic silicon, electrolytic copper, zinc ingot, aluminum manganese intermediate alloy, aluminum chromium intermediate alloy, aluminum vanadium intermediate alloy, aluminum molybdenum intermediate alloy, and aluminum zirconium intermediate alloy. Mechanical stirring is applied to the melt during the holding and melting period to uniformly disperse the alloy elements. After the above furnace charge is melted and uniformly stirred, the temperature is lowered to 750℃, and then the aluminum beryllium intermediate alloy, aluminum scandium intermediate alloy, aluminum gadolinium intermediate alloy, and aluminum dysprosium intermediate alloy are added. After complete melting, the temperature is held at 750℃ for melting and mechanical stirring to uniformly disperse the alloy elements. After the above furnace charge is melted and uniformly stirred, the temperature is lowered to 740℃, and then the magnesium ingot and gallium-indium alloy are added. After complete melting, the temperature is held at 720℃-740℃ for melting and mechanical stirring to uniformly disperse the alloy elements. Then a small amount of sample is taken from the high-temperature aluminum alloy melt after solidification for chemical composition analysis. If the composition deviates, the composition is adjusted and the sample is analyzed again until all elements reach the expected index. (3) A mixed gas composed of 99.99% high-purity argon accounting for 28%, 99.99% high-purity nitrogen accounting for 70%, and 99.99% high-purity chlorine accounting for 2% is used for one-time refining treatment of the aluminum alloy melt in the furnace. The treatment time is 60 minutes. Then the slag in the furnace is removed. After refining, the sample is analyzed again. If the composition is still within the expected index range, it is not necessary to be treated and enters the next process. If the composition deviates, the composition is adjusted and the sample is analyzed again for secondary refining and slag removal treatment until all elements reach the expected index to enter the next process. (4) When the temperature of the aluminum alloy melt in the smelting furnace reaches 700-720 °C, the aluminum alloy melt is discharged from the bottom of the smelting furnace for casting. When the aluminum alloy melt enters the runner, an aluminum-titanium-boron master alloy wire is added to it for grain refinement treatment. After the aluminum alloy melt is subjected to double-stage filtration treatment by a first-stage filter plate with a mesh size of 60 and a second-stage filter plate with a mesh size of 80, it enters an automatic casting machine for casting to obtain a heat treatment-free die casting aluminum alloy ingot. The temperature of the aluminum alloy melt above the casting mold is 705 °C, and a heat treatment-free die casting alloy material is obtained, with a weight of about 5 kg per piece.

[0050] The high-pressure die casting process of the die casting is as follows.

[0051] Step (1) The heat treatment-free die casting aluminum alloy ingot prepared is remelted at 745 °C and stirred to disperse the alloying elements uniformly. Step (2) When the temperature of the aluminum alloy melt decreases to 730 °C, the alloy melt is subjected to refining treatment using a mixed gas composed of 99.99% high-purity argon gas at a proportion of 28%, 99.99% high-purity nitrogen gas at a proportion of 70%, and 99.99% high-purity chlorine gas at a proportion of 2%. The refining lasts for 20 minutes, followed by slagging, and the temperature is controlled at 685 °C for holding, in preparation for high-pressure die casting. The aluminum alloy melt in the smelting furnace is required to be maintained at 685 °C throughout the high-pressure die casting process. Step (3) A certain amount of alloy melt is transferred from the smelting furnace to the cold chamber die casting machine cylinder by using an automatic soup taking mechanical arm for high-pressure die casting. During the die casting process, the first-stage injection speed is 0.40 m / s, the second-stage injection speed is 4.0 m / s, the third-stage injection speed is 15.0 m / s, the die casting pressure is 95 MPa, and after holding for 90 seconds, the workpiece is taken out of the die casting machine mold by using a mechanical hand, and a die casting is obtained after cooling.

[0052] Comparative Example 1 A die casting produced using ADC12 alloy is used for comparison. The mass percentage composition of the ADC12 alloy is as follows: Si: 11.2%, Mg: 0.19%, Cu: 2.0%, Mn: 0.42%, Zn: 0.66%, Ti: 0.13%, Fe: 0.87%, other unavoidable single impurity elements ≤0.03%, total amount of impurity elements ≤0.15%, and the balance is aluminum. The die casting temperature of the ADC12 alloy is 660 °C. During the die casting process, the first-stage injection speed is 0.4 m / s, the second-stage injection speed is 4.5 m / s, the third-stage injection speed is 15.0 m / s, the die casting pressure is 80 MPa, and a die casting is obtained after cooling.

[0053] Comparative Example 2 The die casting produced by the A380 alloy is used for comparison, and the A380 alloy has the following components by mass percentage: Si: 8.0%, Mg: 0.09%, Cu: 3.4%, Mn: 0.40%, Ni: 0.36%, Zn: 1.8%, Ti: 0.08%, Fe: 1.04%, unavoidable single impurity elements ≤0.03%, total amount of impurity elements ≤0.15%, and the balance is aluminum. The die casting temperature of the A380 alloy is 670℃, the first-stage injection speed is 0.4m / s, the second-stage injection speed is 4.0m / s, the third-stage injection speed is 15.0m / s, the die casting pressure is 80MPa, and the die casting workpiece is obtained after cooling.

[0054] Performance test The die castings produced by the above examples 1-3 and the die castings produced by comparative examples 1 and 2 are tested as follows: 1. Mechanical property test The die castings produced by examples 1-3 and comparative examples 1 and 2 are sampled for mechanical property test, the mechanical property test of the present application is tested according to GB / T 228.1-2021, and the yield strength, tensile strength and elongation after fracture are investigated. The results are shown in Table 1.

[0055] Table 1: Performance test results of examples 1-3 and comparative examples 1 and 2

[0056] As can be seen from Table 1, the mechanical properties and plasticity of the die castings obtained by examples 1-3 are better than those of the die castings produced by ADC12 and A380 alloy, and have excellent performance.

[0057] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the specific embodiments of the present application can be modified or replaced by the same, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered in the protection scope of the claims of the present application.

Claims

1. A heat-free die-cast alloy material, characterized in that, Components including the following mass fractions: Si: 1.0~4.0%, Mg: 1.5~8.5%, Cu: 0.03~3.0%, Zn: 0.03~3.0%, Fe≤0.2%, Mn: 0.05~0.8%, Cr: 0.05~0.6%, Ti: 0.03~0.3%, V: 0.01~0.3%, Mo: 0.01~0.3%, Zr: 0.03~0.3%, In: 0.001~0.05%, Ga: 0.001~0.05%, B: 0.005~0.06%, Be: 0.0003~0.002%, Sc: 0.03~0.4%, Gd: 0.03~0.4%, Dy: 0.03~0.4%, with the balance being aluminum.

2. The heat-free die-cast alloy material according to claim 1, characterized in that, The alloy material is obtained from aluminum ingots, metallic silicon, magnesium ingots, electrolytic copper, zinc ingots, aluminum-manganese master alloy, aluminum-chromium master alloy, aluminum-titanium-boron master alloy, aluminum-vanadium master alloy, aluminum-molybdenum master alloy, aluminum-zirconium master alloy, gallium-indium alloy, aluminum-beryllium master alloy, aluminum-scandium master alloy, aluminum-gadolinium master alloy, and aluminum-dysprosium master alloy. The gallium-indium alloy contains 30-60% gallium and 40-70% indium. The contents of scandium, gadolinium, and dysprosium in the aluminum-scandium master alloy, aluminum-gadolinium master alloy, and aluminum-dysprosium master alloy are 1.95~2.10%, 9.5~10.5%, and 4.8~5.2%, respectively. The mass ratio of scandium, gadolinium, and dysprosium in the alloy material is (1~2):(2~4):(1~5).

3. A method for preparing a heat-free die-cast alloy material according to any one of claims 1 to 2, characterized in that, Includes the following steps: Step (1), prepare raw materials: aluminum ingots, metallic silicon, magnesium ingots, electrolytic copper, zinc ingots, aluminum manganese master alloy, aluminum chromium master alloy, aluminum titanium boron master alloy, aluminum vanadium master alloy, aluminum molybdenum master alloy, aluminum zirconium master alloy, gallium indium alloy, aluminum beryllium master alloy, aluminum scandium master alloy, aluminum gadolinium master alloy, aluminum dysprosium master alloy; Step (2): The first batch of raw materials is loaded into the melting furnace, heated and melted and kept at the temperature for the first stage of melting. The first batch of raw materials includes: aluminum ingots, metallic silicon, electrolytic copper, zinc ingots, aluminum-manganese master alloy, aluminum-chromium master alloy, aluminum-vanadium master alloy, aluminum-molybdenum master alloy, and aluminum-zirconium master alloy. During the melting process, mechanical stirring is applied to the melt. After the first batch of raw materials is melted, a second batch of raw materials is added for the second stage of smelting. The second batch of raw materials includes: aluminum-beryllium master alloy, aluminum-scandium master alloy, aluminum-gadolinium master alloy, and aluminum-dysprosium master alloy. During the smelting process, mechanical stirring is applied to the melt. After the second batch of raw materials is melted, a third batch of raw materials is added for the third stage of smelting. The third batch of raw materials includes magnesium ingots and gallium-indium alloy. During the smelting process, mechanical stirring is applied to the melt to obtain an aluminum alloy melt. Step (3) The aluminum alloy melt obtained in step (2) is refined once, and then the slag in the furnace is removed. After the refining is completed, the sample is taken for analysis again. If the composition is still within the expected index range, no further processing is required to proceed to the next process. If the composition deviates, the composition is adjusted and the sample is taken for analysis again, and a second refining and slag removal process is carried out until all elements reach the expected index before proceeding to the next process. Step (4): The aluminum alloy melt is released from the bottom of the furnace for casting. When the aluminum alloy melt enters the flow channel, aluminum-titanium-boron intermediate alloy wire is added to it for grain refinement treatment. After the aluminum alloy melt undergoes double-stage filtration treatment, it enters the automatic casting machine for casting to obtain the heat-free die-cast alloy material.

4. The preparation method according to claim 3, characterized in that, The melting temperature in the first stage is 760~800℃, the melting temperature in the second stage is 740~780℃, and the melting temperature in the third stage is 720~760℃.

5. The preparation method according to claim 3, characterized in that, The mixed gas used in the primary refining process is made of high-purity argon, high-purity nitrogen, and high-purity chlorine, with high-purity argon accounting for 28%, high-purity nitrogen accounting for 70%, and high-purity chlorine accounting for 2%. The primary refining process takes 30 to 60 minutes. The temperature and gas used in the secondary refining process are the same as those in the primary refining process, and the secondary refining process takes 15 to 30 minutes.

6. The preparation method according to claim 3, characterized in that, In the dual-stage filtration, the first-stage filter plate is 60 mesh and the second-stage filter plate is 80 mesh; during the casting process, the temperature of the aluminum alloy melt above the mold plate is maintained at 640~720℃.

7. The application of the heat-free die-casting alloy material according to any one of claims 1 to 2 in die-cast products.

8. A method for preparing a die-cast part, characterized in that, Includes the following steps: The heat-free die-cast alloy material is remelted and stirred to obtain an alloy melt; The alloy melt is refined, then slag is removed and the melt is kept at a constant temperature. Finally, the alloy melt is die-cast to obtain the die-cast part.

9. The preparation method according to claim 8, characterized in that, The heat-free die-casting alloy material is the heat-free die-casting alloy material prepared according to claim 3; the remelting temperature is 720~760℃; the refining temperature is 710~730℃ and the time is 10~30 minutes; the mixed gas used in the refining process is made of high-purity argon, high-purity nitrogen and high-purity chlorine, wherein high-purity argon accounts for 28%, high-purity nitrogen accounts for 70% and high-purity chlorine accounts for 2%; the heat preservation temperature is 680~720℃.

10. The preparation method according to claim 8, characterized in that, The die casting process employs high-pressure die casting. During the die casting process, the first-stage injection speed is 0.1~0.5m / s, the second-stage injection speed is 2~5m / s, the third-stage injection speed is 5~20m / s, the die casting pressure is 50~100MPa, and the holding time is 30~90 seconds.

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