A die-casting material for an integrated automotive casting and a casting preparation process

Abstract

The present invention provides a die-casting material for an automotive integrated casting and a casting preparation process, which relates to the technical field of alloy casting processing. The die-casting material for the automotive integrated casting is composed of substances such as copper, magnesium, titanium diboride, zinc, erbium, chromium, manganese, silicon, europium, aluminum, etc., and its preparation process mainly includes steps such as melting of aluminum, mixed forging, secondary melting, secondary mixing, high-temperature melting, secondary forging, raw material mixing, cooling and shaping, grinding and shaping, etc. The present invention overcomes the deficiencies of the prior art, effectively improves the tensile strength of the casting material, further improves the yield strength, and enhances the safety of automotive castings in use.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy casting processing, and particularly relates to a die-casting material for automotive integrated castings and a casting preparation process. Background Art

[0002] Automobiles are now daily means of transportation for people, and the annual production volume of automobiles in China also reaches about 6 million. With the development of new energy, in order to reduce energy consumption, the development of automotive lightweight is also crucial.

[0003] Replacing some steel with cast aluminum alloy can reduce the vehicle weight, save fuel and reduce CO2 emissions. At the same time, for new energy electric vehicles, it can also achieve a certain energy-saving effect and improve the endurance. Automotive structural parts are the load-bearing and force-bearing parts of the vehicle. For structural parts related to strength, the tensile strength ≥ 210 MPa and the elongation ≥ 7%. For structural parts related to toughness, the tensile strength ≥ 180 MPa and the elongation ≥ 10%.

[0004] Ordinary cast aluminum alloys are difficult to meet the requirements of their mechanical properties and service performance. By adding alloying elements to aluminum alloys, their service performance can be greatly improved. At present, Al-Si series and Al-Mg series cast aluminum alloys are most widely used in automotive structural parts. However, generally speaking, for the rapidly developing automotive industry, the demand for the performance of aluminum alloys is also getting higher and higher. Therefore, how to improve the comprehensive performance of aluminum alloys is also an important development direction in the field of automotive manufacturing. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a die-casting material for automotive integrated castings and a casting preparation process, which can effectively improve the tensile strength of the casting material, further improve the yield strength, and enhance the safety of automotive castings.

[0006] To achieve the above objectives, the technical solution of the present invention is realized through the following technical solutions:

[0007] A die-casting material for automotive integrated castings, the die-casting material is made of the following raw materials by weight percentage: silicon 4%-8%, magnesium 3%-5%, titanium diboride 2%-4%, zinc 9%-10%, erbium 0.2%-0.4%, chromium 3%-6%, manganese 2%-4%, copper 1%-1.6%, europium 0.2%-0.8%, and the total amount of other impurities is <0.2%, and the balance is aluminum.

[0008] Preferably, the particle size diameter of the titanium diboride is 100 nm - 1.0 μm.

[0009] The automotive casting using the above preparation process includes the following steps:

[0010] (1) Thermal melting of aluminum: Place aluminum ingots in a high-temperature electric furnace, heat up to 660 - 700 °C, then let it stand for 15 - 20 minutes, add a slag removal agent and mix and stir for 5 - 8 minutes, then perform slag removal. Continue to heat the slag-removed aluminum liquid to 750 - 800 °C, then keep it warm and stand still to obtain molten metal A for standby;

[0011] (2) Mixed forging: Add magnesium to the above molten metal A, then adjust the temperature to 680 - 700 °C and place it in a forging furnace to stand still, then perform high-temperature forging at a temperature of 500 - 600 °C to obtain forged alloy for standby;

[0012] (3) Secondary thermal melting: Place the above forged alloy in an electric furnace and heat up to 1500 °C - 1700 °C for thermal melting for 30 - 40 minutes, then add erbium to it and adjust the temperature to 1200 - 1300 °C, keep it warm and stand still for thermal melting for 20 - 30 minutes to obtain molten metal B for standby;

[0013] (4) Secondary mixing: Mix copper, chromium and zinc and place them in the above molten metal B, place them in a high-temperature environment of 1100 - 1200 °C and mechanically stir for 15 - 20 minutes to obtain molten metal C for standby;

[0014] (5) High-temperature thermal melting: Add the above molten metal C to a high-temperature reaction kettle, then add titanium diboride and europium, and perform high-temperature thermal melting and standing still in a high-temperature environment of 1850 - 1950 °C to obtain molten metal D for standby;

[0015] (6) Secondary forging: Slowly cool the above molten metal D to 600 - 650 °C, then perform repeated forging, and then take out the forged product and cool it to 100 - 120 °C at room temperature to obtain mixed metal for standby;

[0016] (7) Raw material mixing: Mix chromium, manganese and silicon and place them in a high-temperature reaction furnace, mix and thermally melt them in a high-temperature environment of 1910 - 1950 °C for 10 - 15 minutes, then add the above mixed metal, adjust the temperature to 1200 - 1400 °C, perform heat preservation and inoculation for 2 - 3 hours to obtain mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain alloy liquid for standby;

[0017] (8) Cooling and shaping: Cool the above alloy liquid to a temperature of 1000 - 1100 °C, then pour the alloy liquid into a mold, slowly cool it to 400 - 450 °C and keep it warm and stand still for 30 - 40 minutes, then continue to slowly cool it to 100 - 200 °C, continue to stand still for 1 - 2 hours, and then cool it to room temperature at room temperature and demold it to obtain a casting blank;

[0018] (9) Grinding and forming: Heat the above-mentioned casting blank to 100 - 120 °C, keep it warm and static for 15 - 20 min, then cool it to 60 - 70 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain an automotive casting. The mass percentage of the raw material composition of the automotive casting is: silicon 4% - 8%, magnesium 3% - 5%, titanium diboride 2% - 4%, zinc 9% - 10%, erbium 0.2% - 0.4%, chromium 3% - 6%, manganese 2% - 4%, copper 1% - 1.6%, europium 0.2% - 0.8%, the total of other impurities < 0.2%, and the balance is aluminum.

[0019] Preferably, the slag remover added in the step (1) is a mixture of silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide with a mass ratio of 8:1:2:0.4, and the addition amount of the slag remover is 0.2% - 0.4% of the mass of the aluminum ingot.

[0020] Preferably, the time for high-temperature static placement at 680 - 700 °C in the step (2) is 50 - 60 min, and the forging time is 15 - 20 min.

[0021] Preferably, the rotation speed of the mechanical stirring in the step (4) is 80 - 100 r / min.

[0022] Preferably, the time for hot melt static placement in the step (5) ≥ 40 min.

[0023] Preferably, the rate of slow cooling in the step (6) is to cool at a rate of 5 - 8 °C / min, and the time for repeated forging is 25 - 30 min.

[0024] Preferably, the rate of slow cooling in the step (8) is to cool at a rate of 3 - 5 °C / min.

[0025] The present invention provides a die-casting material for automotive integrated castings and a casting preparation process, and the advantages compared with the prior art are as follows:

[0026] (1) In the present invention, by adding titanium diboride instead of titanium metal, the strength of the aluminum alloy is effectively improved. At the same time, by controlling the addition amount at 2% - 4%, the toughness of the alloy material can be effectively improved;

[0027] (2) Adding erbium and europium in the present invention effectively ensures the stability of the alloy, improves the comprehensive performance of the alloy, prevents the alloy from cracking during forging, and improves the yield rate;

[0028] (3) In the present invention, through multiple times of mixing and hot melting, the uniformity and stability of the mixing of various metals are improved, the strength of the later aluminum alloy is enhanced, and at the same time, the elasticity of the aluminum alloy is ensured, so that the prepared casting has good toughness and anti-collision performance, and the safety of using automotive castings is improved. Specific embodiments

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0030] Embodiment 1:

[0031] Preparation of automotive integrated castings:

[0032] (1) Preparation of materials: Prepare materials according to the following raw materials by weight percentage: silicon 4%, magnesium 3%, titanium diboride 2%, zinc 9%, erbium 0.2%, chromium 3%, manganese 2%, copper 1%, europium 0.2%, and the total of other impurities <0.2%, with the balance being aluminum.

[0033] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide in a mass ratio of 8:1:2:0.4 to obtain the slag remover for standby;

[0034] (3) Thermal melting of aluminum: Place aluminum ingots in a high-temperature electric furnace, heat up to 660 °C, then let it stand for 15 min, add 0.2% of the slag remover based on the mass of the aluminum ingots, mix and stir for 5 min, then remove the slag. Continue to heat the deslagged aluminum liquid to 750 °C and keep it warm and standing to obtain molten metal A for standby;

[0035] (4) Mixed forging: Add magnesium to the above molten metal A, then adjust the temperature to 680 °C, place it in a forging furnace and let it stand for 50 min, then perform high-temperature forging at 500 °C for 15 min to obtain the forged alloy for standby;

[0036] (5) Secondary thermal melting: Place the above forged alloy in an electric furnace, heat up to 1500 °C and perform thermal melting for 30 min, then add erbium to adjust the temperature to 1200 °C, keep it warm and standing for thermal melting for 20 min to obtain molten metal B for standby;

[0037] (6) Secondary mixing: Mix copper, chromium, and zinc and place them in the above molten metal B in a high-temperature environment of 1100 °C and perform mechanical stirring at a rotation speed of 80 r / min for 15 min to obtain molten metal C for standby;

[0038] (7) High-temperature thermal melting: Add the above molten metal C to a high-temperature reaction kettle, then add titanium diboride and europium and perform high-temperature thermal melting in a high-temperature environment of 1850 °C. Let it stand for 40 min to obtain molten metal D for standby;

[0039] (8) Secondary forging: Slowly cool the above-mentioned molten metal D at a rate of 5 °C / min to 600 °C, then perform repeated forging for 25 min, and then take out the forging product and cool it to 100 °C at room temperature to obtain the mixed metal for standby;

[0040] (9) Raw material mixing: Mix chromium, manganese, and silicon and place them in a high-temperature reaction furnace. Mix and melt them at a high temperature of 1910 °C for 10 min, then add the above-mentioned mixed metal, adjust the temperature to 1200 °C, and carry out heat preservation and inoculation for 2 h to obtain the mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain the alloy liquid for standby;

[0041] (10) Cooling and shaping: Cool the above-mentioned alloy liquid to a temperature of 1000 °C, then pour the alloy liquid into a mold, slowly cool it at a rate of 3 °C / min to 400 °C, then keep it warm and static for 30 min, and then continue to slowly cool it to 100 °C. After continuing to stand for 1 h, cool it to room temperature at room temperature and then demold to obtain the casting blank;

[0042] (11) Grinding and shaping: Heat the above-mentioned casting blank to 100 °C and keep it warm and static for 15 min, then cool it to 60 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain the automotive casting.

[0043] Example 2:

[0044] Preparation of automotive integrated casting:

[0045] (1) Material preparation: Prepare materials according to the following raw materials by weight percentage: silicon 8%, magnesium 5%, titanium diboride 4%, zinc 10%, erbium 0.4%, chromium 6%, manganese 4%, copper 1.6%, europium 0.8%, and the total of other impurities is <0.2%, and the balance is aluminum.

[0046] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide according to a mass ratio of 8:1:2:0.4 to obtain the slag remover for standby;

[0047] (3) Melting of aluminum: Place the aluminum ingot in a high-temperature electric furnace, heat it to 700 °C, then stand for 20 min, add 0.3% of the slag remover based on the mass of the aluminum ingot, mix and stir for 8 min, then remove the slag, and continue to heat the molten aluminum after slag removal to 800 °C and keep it warm and static to obtain the molten metal A for standby;

[0048] (4) Mixed forging: Add magnesium to the above-mentioned molten metal A, then adjust the temperature to 700 °C, place it in a forging furnace and stand for 60 min, and then perform high-temperature forging at 600 °C for 20 min to obtain the forged alloy for standby;

[0049] (5) Secondary melting: Heat the above-mentioned forged alloy in an electric furnace to 1700 °C for 40 minutes of melting, then add erbium to it, adjust the temperature to 1300 °C, keep it warm and static for 30 minutes of melting to obtain molten metal B for standby;

[0050] (6) Secondary mixing: Mix copper, chromium and zinc and place them in the above-mentioned molten metal B. Place them in a high-temperature environment of 1200 °C and carry out mechanical stirring at a speed of 100 r / min for 20 minutes, then obtain molten metal C for standby;

[0051] (7) High-temperature melting: Add the above-mentioned molten metal C into a high-temperature reaction kettle, then add titanium diboride and europium and carry out high-temperature melting in a high-temperature environment of 1950 °C. After standing for 50 minutes, obtain molten metal D for standby;

[0052] (8) Secondary forging: Slowly cool the above-mentioned molten metal D to 650 °C at a speed of 8 °C / min, then carry out repeated forging for 30 minutes, and then take out the forging product and cool it to 120 °C at room temperature to obtain the mixed metal for standby;

[0053] (9) Raw material mixing: Mix chromium, manganese and silicon and place them in a high-temperature reaction furnace. Mix and melt them in a high-temperature environment of 1950 °C for 15 minutes, then add the above-mentioned mixed metal, adjust the temperature to 1400 °C, carry out heat preservation and inoculation for 3 hours to obtain the mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain the alloy liquid for standby;

[0054] (10) Cooling and shaping: Cool the above-mentioned alloy liquid to a temperature of 1100 °C, then pour the alloy liquid into a mold, slowly cool it to 450 °C at a speed of 5 °C / min, then keep it warm and static for 40 minutes, then continue to slowly cool it to 200 °C, continue to stand for 2 hours, and then cool it to room temperature at room temperature and demold to obtain the casting blank;

[0055] (11) Grinding and shaping: Heat the above-mentioned casting blank to 120 °C, then keep it warm and static for 20 minutes, then cool it to 70 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain the automotive casting.

[0056] Example 3:

[0057] Preparation of automotive integrated casting:

[0058] (1) Preparation of materials: Prepare materials according to the following raw materials by weight percentage: silicon 6%, magnesium 4%, titanium diboride 3%, zinc 9.5%, erbium 0.3%, chromium 5%, manganese 3%, copper 1.3%, europium 0.5%, and the total of other impurities <0.2%, and the balance is aluminum.

[0059] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide and iron(III) oxide according to a mass ratio of 8:1:2:0.4 to obtain the slag remover for standby;

[0060] (3) Thermal melting of aluminum: Place the aluminum ingot in a high-temperature electric furnace, heat it up to 700 °C, then let it stand for 18 min, add a slag-removing agent accounting for 0.3% of the mass of the aluminum ingot, mix and stir for 6 min, then remove the slag. Continue to heat the molten aluminum to 750 °C, then keep it warm and static to obtain molten metal A for standby;

[0061] (4) Mixed forging: Add magnesium to the above-mentioned molten metal A, then adjust the temperature to 690 °C, place it in a forging furnace and let it stand for 55 min, then perform high-temperature forging at 550 °C for 18 min to obtain forged alloy for standby;

[0062] (5) Secondary thermal melting: Place the above-mentioned forged alloy in an electric furnace, heat it up to 1600 °C for thermal melting for 35 min, then add erbium to it, adjust the temperature to 1250 °C, keep it warm and static for thermal melting for 25 min to obtain molten metal B for standby;

[0063] (6) Secondary mixing: Mix copper, chromium and zinc and place them in the above-mentioned molten metal B in a high-temperature environment of 1150 °C, perform mechanical stirring at a speed of 90 r / min for 18 min, then obtain molten metal C for standby;

[0064] (7) High-temperature thermal melting: Add the above-mentioned molten metal C to a high-temperature reaction kettle, then add titanium diboride and europium, and perform high-temperature thermal melting in a high-temperature environment of 1900 °C. After standing for 45 min, obtain molten metal D for standby;

[0065] (8) Secondary forging: Slowly cool the above-mentioned molten metal D to 600 °C at a speed of 7 °C / min, then perform repeated forging for 28 min, and then take out the forged product and cool it to 110 °C at room temperature to obtain mixed metal for standby;

[0066] (9) Raw material mixing: Mix chromium, manganese and silicon and place them in a high-temperature reaction furnace, perform mixed thermal melting in a high-temperature environment of 1900 °C for 13 min, then add the above-mentioned mixed metal, adjust the temperature to 1300 °C, perform heat preservation and inoculation for 2.5 h to obtain mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain alloy liquid for standby;

[0067] (10) Cooling and shaping: Cool the above-mentioned alloy liquid to 1050 °C, then pour the alloy liquid into a mold, slowly cool it to 430 °C at a speed of 4 °C / min, then keep it warm and static for 35 min, then continue to slowly cool it to 150 °C, continue to stand for 1.5 h, and then cool it to room temperature at room temperature and demold to obtain a casting blank;

[0068] (11) Grinding and shaping: Heat the above-mentioned casting blank to 110 °C, then keep it warm and static for 18 min, then cool it to 65 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain an automotive casting.

[0069] Comparative Example 1:

[0070] Preparation of integrated automotive castings:

[0071] (1) Material preparation: Prepare materials according to the following raw materials by weight percentage: silicon 6%, magnesium 4%, titanium 3%, zinc 9.5%, erbium 1%, chromium 4.5%, manganese 3%, copper 1.3%, europium 0.5%, and the total amount of other impurities is <0.2%, with the balance being aluminum.

[0072] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide in a mass ratio of 8:1:2:0.4 to obtain the slag remover for standby;

[0073] (3) Thermal melting of aluminum: Place aluminum ingots in a high-temperature electric furnace, heat up to 700 °C, then let it stand for 18 min, add 0.3% of the slag remover based on the mass of the aluminum ingots, mix and stir for 6 min, then remove the slag. Continue to heat the molten aluminum to 750 °C and keep it warm and standing to obtain molten metal A for standby;

[0074] (4) Mixed forging: Add magnesium to the above molten metal A, then adjust the temperature to 690 °C, place it in a forging furnace and let it stand for 55 min, and then perform high-temperature forging at 550 °C for 18 min to obtain the forged alloy for standby;

[0075] (5) Secondary thermal melting: Place the above forged alloy in an electric furnace, heat up to 1600 °C and perform thermal melting for 35 min, then add erbium to adjust the temperature to 1250 °C, keep it warm and standing for thermal melting for 25 min to obtain molten metal B for standby;

[0076] (6) Secondary mixing: Mix copper, chromium, and zinc and place them in the above molten metal B in a high-temperature environment of 1150 °C, and perform mechanical stirring at a speed of 90 r / min for 18 min to obtain molten metal C for standby;

[0077] (7) High-temperature thermal melting: Add the above molten metal C to a high-temperature reaction kettle, add titanium and europium, and perform high-temperature thermal melting in a high-temperature environment of 1900 °C. After standing for 45 min, obtain molten metal D for standby;

[0078] (8) Secondary forging: Slowly cool the above molten metal D to 600 °C at a speed of 7 °C / min, then perform repeated forging for 28 min, and then take out the forged product and cool it to 110 °C at room temperature to obtain the mixed metal for standby;

[0079] (9) Raw material mixing: Mix chromium, manganese, and silicon and place them in a high-temperature reaction furnace. Mix and thermally melt them in a high-temperature environment of 1900 °C for 13 min, then add the above mixed metal, adjust the temperature to 1300 °C, and perform heat preservation and inoculation for 2.5 h to obtain the mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain the alloy liquid for standby;

[0080] (10) Cooling and setting: Cool the above alloy liquid to a temperature of 1050 °C, then pour the alloy liquid into a mold, slowly cool it at a rate of 4 °C / min to 430 °C, keep it warm and static for 35 min, then continue to slowly cool it to 150 °C, continue to static for 1.5 h, and then cool it to room temperature at normal temperature and demold to obtain a casting blank;

[0081] (11) Grinding and shaping: Heat the above casting blank to 110 °C, keep it warm and static for 18 min, then cool it to 65 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain an automotive casting.

[0082] Comparative Example 2:

[0083] Preparation of automotive integrated casting:

[0084] (1) Preparation of materials: Prepare materials according to the following raw materials by weight percentage: silicon 6%, magnesium 4%, titanium diboride 3%, zinc 9.5%, chromium 4.5%, manganese 3%, silicon 1.3%, and the total of other impurities is <0.2%, and the balance is aluminum;

[0085] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide according to a mass ratio of 8:1:2:0.4 to obtain a slag remover for standby;

[0086] (3) Thermal melting of aluminum: Place the aluminum ingot in a high-temperature electric furnace, heat it to 700 °C, then static for 18 min, add 0.3% of the slag remover of the aluminum ingot, mix and stir for 6 min, then remove the slag, and continue to heat the slag-removed aluminum liquid to 750 °C, keep it warm and static to obtain molten metal A for standby;

[0087] (4) Mixed forging: Add magnesium to the above molten metal A, then adjust the temperature to 690 °C, place it in a forging furnace and static for 55 min, and then perform high-temperature forging at 550 °C for 18 min to obtain forged alloy for standby;

[0088] (5) Secondary thermal melting: Place the above forged alloy in an electric furnace, heat it to 1600 °C for thermal melting for 35 min, adjust the temperature to 1250 °C, keep it warm and static for thermal melting for 25 min to obtain molten metal B for standby;

[0089] (6) Secondary mixing: Mix copper, chromium, and zinc and place them in the above molten metal B in a high-temperature environment of 1150 °C, and perform mechanical stirring at a rotation speed of 90 r / min for 18 min to obtain molten metal C for standby;

[0090] (7) High-temperature thermal melting: Add the above molten metal C to a high-temperature reaction kettle, add titanium diboride, and perform high-temperature thermal melting at a high-temperature environment of 1900 °C. After static for 45 min, obtain molten metal D for standby;

[0091] (8) Secondary forging: Slowly cool the above-mentioned molten metal D to 600 °C at a rate of 7 °C / min, then perform repeated forging for 28 min, and then take out the forging product and cool it to 110 °C at room temperature to obtain the mixed metal for standby;

[0092] (9) Raw material mixing: Mix chromium, manganese, and silicon and place them in a high-temperature reaction furnace. Mix and melt them at a high temperature of 1900 °C for 13 min, then add the above-mentioned mixed metal, adjust the temperature to 1300 °C, and carry out heat preservation and inoculation for 2.5 h to obtain the mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain the alloy liquid for standby;

[0093] (10) Cooling and shaping: Cool the above-mentioned alloy liquid to a temperature of 1050 °C, then pour the alloy liquid into a mold, slowly cool it to 430 °C at a rate of 4 °C / min and keep it warm and static for 35 min, then continue to slowly cool it to 150 °C, continue to keep it static for 1.5 h, and then cool it to room temperature at room temperature and demold it to obtain the casting blank;

[0094] (11) Grinding and shaping: Heat the above-mentioned casting blank to 110 °C and keep it warm and static for 18 min, then cool it to 65 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain the automotive casting.

[0095] Comparative Example 3:

[0096] Preparation of automotive integrated casting:

[0097] (1) Preparation of materials: Prepare materials according to the following raw materials by weight percentage: silicon 6%, magnesium 4%, titanium diboride 3%, zinc 9.5%, erbium 0.3%, chromium 4.5%, manganese 3%, copper 1.3%, europium 0.5%, and the total of other impurities is <0.2%, and the balance is aluminum.

[0098] (2) Preparation of slag remover: Mix silicon dioxide, calcium oxide, magnesium oxide, and iron(III) oxide according to a mass ratio of 8:1:2:0.4 to obtain the slag remover for standby;

[0099] (3) Melting of aluminum: Place the aluminum ingot in a high-temperature electric furnace, heat it to 700 °C, then keep it static for 18 min, add 0.3% of the slag remover based on the mass of the aluminum ingot, mix and stir for 6 min, and then carry out slag removal. Continue to heat the slag-removed aluminum liquid to 750 °C and keep it warm and static to obtain the molten metal A for standby;

[0100] (4) Mixed forging: Add copper, magnesium, titanium diboride, zinc, erbium, chromium, manganese, silicon, and europium to the above-mentioned molten metal A, then adjust the temperature to 1900 °C in a high-temperature environment and mix and melt for 13 min, and then adjust the temperature to 1300 °C for heat preservation and inoculation for 2.5 h to obtain the mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain the alloy liquid for standby;

[0101] (5) Cooling and shaping: Cool the above alloy liquid to a temperature of 1050 °C, then pour the alloy liquid into a mold, slowly cool it at a rate of 4 °C / min to 430 °C, keep it warm and static for 35 min, then continue to slowly cool it to 150 °C, continue to keep it static for 1.5 h, and then cool it to room temperature at normal temperature and demold to obtain a casting blank;

[0102] (6) Grinding and shaping: Heat the above casting blank to 110 °C, keep it warm and static for 18 min, then cool it to 65 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain an automotive casting.

[0103] Detection:

[0104] Select the casting materials obtained in the above Examples 1-3 and Comparative Examples 1-3 and conduct tensile strength and yield strength tests according to the detection standard of GB / T16865-2013. At the same time, use the GB / T16865-2013 standard to detect the elongation at break. The specific results are shown in the following table:

[0105] Group Tensile strength (MPa) Yield strength (MPa) Elongation at break (%) Experimental group 1 386 341 8.1 Experimental group 2 394 346 7.9 Experimental group 3 389 343 8.0 Control group 1 352 307 7.5 Control group 2 329 289 6.8 Control group 3 361 332 7.6

[0106] As can be seen from the above table, the addition of various substances in the present invention can effectively improve the various properties of alloy castings, and the method of multiple melting can also improve the properties of the alloy to a certain extent.

[0107] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A die-casting material for an integrated automotive casting, characterized in that, The die-casting material is made of the following raw materials by weight percentage: 4%-8% of silicon, 3%-5% of magnesium, 2%-4% of titanium diboride, 9%-10% of zinc, 0.2%-0.4% of erbium, 3%-6% of chromium, 2%-4% of manganese, 1%-1.6% of copper, 0.2%-0.8% of europium, with the total amount of other impurities <0.2%, and the balance being aluminum.

2. The die-casting material for an integrated casting of an automobile according to claim 1, wherein: The particle size diameter of the titanium diboride is 100nm - 1.0μm.

3. A preparation process for an integrated casting of an automobile, characterized in that, The preparation process of the automotive casting includes the following steps: (1) Melting of aluminum: Place the aluminum ingot in a high-temperature electric furnace, heat it up to 660 - 700°C, then let it stand for 15 - 20 minutes, add a slag remover and mix and stir for 5 - 8 minutes, then remove the slag. Continue to heat the aluminum liquid after slag removal to 750 - 800°C and keep it warm and standing to obtain molten metal A for standby. (2) Mixing and forging: Add magnesium to the above molten metal A, then adjust the temperature to 680 - 700°C and let it stand in a forging furnace, and then perform high-temperature forging at a temperature of 500 - 600°C to obtain forged alloy for standby. (3) Secondary melting: Place the above forged alloy in an electric furnace and heat it up to 1500°C - 1700°C for melting for 30 - 40 minutes, then add erbium to it and adjust the temperature to 1200 - 1300°C, keep it warm and standing for melting for 20 - 30 minutes to obtain molten metal B for standby. (4) Secondary mixing: Mix copper, chromium and zinc and place them in the above molten metal B in a high-temperature environment of 1100 - 1200°C and mechanically stir for 15 - 20 minutes to obtain molten metal C for standby. (5) High-temperature melting: Add the above molten metal C to a high-temperature reaction kettle, then add titanium diboride and europium and carry out high-temperature melting and standing in a high-temperature environment of 1850 - 1950°C to obtain molten metal D for standby. (6) Secondary forging: Slowly cool the above molten metal D to 600 - 650°C, then carry out repeated forging, and then take out the forged product and cool it to 100 - 120°C at room temperature to obtain mixed metal for standby. (7) Raw material mixing: Mix chromium, manganese and silicon and place them in a high-temperature reaction furnace, mix and melt them in a high-temperature environment of 1910 - 1950°C for 10 - 15 minutes, then add the above mixed metal, adjust the temperature to 1200 - 1400°C, carry out heat preservation and inoculation for 2 - 3 hours to obtain mixed molten metal. After skimming the slag, detect the content of each component and adjust it to the required range to obtain alloy liquid for standby. (8) Cooling and shaping: Cool the above alloy liquid to a temperature of 1000 - 1100°C, then pour the alloy liquid into a mold, slowly cool it to 400 - 450°C and keep it warm and standing for 30 - 40 minutes, then continue to slowly cool it to 100 - 200°C, continue to stand for 1 - 2 hours, and then cool it to room temperature at room temperature and demold to obtain a casting blank. (9) Grinding and forming: Heat the above-mentioned casting blank to 100 - 120 °C, keep it warm and static for 15 - 20 min, then cool it to 60 - 70 °C for surface polishing and grinding, and then use micro-arc oxidation technology to treat the blank to obtain an automotive casting. The mass percentage of the raw material composition of the automotive casting is as follows: silicon 4% - 8%, magnesium 3% - 5%, titanium diboride 2% - 4%, zinc 9% - 10%, erbium 0.2% - 0.4%, chromium 3% - 6%, manganese 2% - 4%, copper 1% - 1.6%, europium 0.2% - 0.8%, the total of other impurities is < 0.2%, and the balance is aluminum.

4. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: The slag remover added in the step (1) is a mixture of silica, calcium oxide, magnesium oxide, and iron(III) oxide with a mass ratio of 8:1:2:0.4, and the addition amount of the slag remover is 0.2% - 0.4% of the mass of the aluminum ingot.

5. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: In the step (2), the time for high-temperature static at 680 - 700 °C is 50 - 60 min, and the forging time is 15 - 20 min.

6. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: In the step (4), the rotation speed of the mechanical stirring is 80 - 100 r / min.

7. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: In the step (5), the time for hot melting and static is ≥ 40 min.

8. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: In the step (6), the speed of slow cooling is 5 - 8 °C / min for cooling, and the time for repeated forging is 25 - 30 min.

9. The preparation process of an integrated casting for an automobile according to claim 3, characterized in that: In the step (8), the speed of slow cooling is 3 - 5 °C / min for cooling.