阅读说明：本技术 一种高性能铝合金压铸件及其制备方法 (High-performance aluminum alloy die casting and preparation method thereof ) 是由 张真 魏海根 夏承东 吴勇 龙昌 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种高性能铝合金压铸件的制备方法,包括以下步骤：S1：准确称取铝合金组分原料；S2：先将部分原料放入熔炼炉中,加热到700-750℃,向熔炼炉中排入氩气,保温20-30min；S3：向熔炼炉喷入余下原料,升温到850-900℃,保温25-30min；S4：向炉内喷入精炼剂,进行精炼,进行第扒渣,完成精炼；S5：向模具浇注铝合金溶液,直至充型压铸结束；S6：压铸结束后保压时间为120-150s,卸掉压力,冷却20-25s后脱模冷却,将脱模冷却后的压铸件进行冷锻,制成铝合金压铸件。本发明具有良好的机械性能：抗拉强度大于350Mpa,延伸率大于4.5％,硬度大于105HV；压铸件具有强度高、耐腐蚀、韧性大等优点。(The invention discloses a preparation method of a high-performance aluminum alloy die casting, which comprises the following steps: s1: accurately weighing the aluminum alloy component raw materials; s2: firstly, putting part of raw materials into a smelting furnace, heating to 700-750 ℃, discharging argon into the smelting furnace, and preserving heat for 20-30 min; s3: spraying the rest raw materials into the smelting furnace, heating to 850-; s4: spraying a refining agent into the furnace, refining, slagging off and finishing refining; s5: pouring an aluminum alloy solution into the die until the mold filling and die casting are finished; s6: and (3) keeping the pressure for 150 seconds after the die casting is finished, removing the pressure, cooling for 20-25 seconds, demoulding and cooling, and performing cold forging on the die casting after demoulding and cooling to obtain the aluminum alloy die casting. The invention has good mechanical properties: the tensile strength is more than 350Mpa, the elongation is more than 4.5 percent, and the hardness is more than 105 HV; the die casting has the advantages of high strength, corrosion resistance, high toughness and the like.)

1. A preparation method of a high-performance aluminum alloy die casting is characterized by comprising the following steps: the method comprises the following steps:

s1: accurately weighing the following components in percentage by mass: 8.0-12.0% of pure silicon ingot, 3.0-5.5% of pure magnesium ingot, 1.2-2.5% of pure zinc ingot, 2.5-4.0% of pure copper ingot, 0.5-0.8% of rare earth element alloy, 0.03-0.05% of Sr0.05-0.1% of Er0.05-0.1% of pure aluminum ingot;

s2: firstly, putting aluminum, a pure silicon ingot, a pure magnesium ingot, a pure zinc ingot and a pure copper ingot into a smelting furnace, enabling the smelting furnace to be in an exhaust state, heating to 700-750 ℃, discharging argon into the smelting furnace, evacuating the air in the smelting furnace, pressurizing to 0.3-0.5MPa, and preserving heat for 20-30 min;

s3: spraying alloy of rare earth elements, Sr and Er powder into a smelting furnace in sequence, stirring and melting, heating to 850-900 ℃, and preserving heat for 25-30 min;

s4: cooling the aluminum alloy solution in the furnace body to 750-doped 780 ℃, spraying a refining agent into the furnace for refining, after refining for 5-10min, carrying out pressure relief and slagging off, after slagging off is finished, introducing argon to increase heat preservation for 15-20min, carrying out secondary slagging off, finishing refining, cooling to 650-doped 700 ℃, and detecting the aluminum alloy solution;

s5: preheating the cavity of the die to 250-300 ℃, injecting the aluminum alloy melt processed in the step S4 into the cavity of the die, wherein the flow rate of the melt at the beginning of mold filling is 0.35-0.40m/S, the casting pressure is 45-50MPa, and after the mold filling rate exceeds 50%, the flow rate of the melt is increased to 1.5-2.0m/S, and the casting pressure is 70-85MPa until the mold filling and die casting are finished;

s6: after the die casting is finished, the pressure maintaining time is 120-150s, the pressure is removed, and the die is removed and cooled after being cooled for 20-25 s;

s7: and (5) performing cold forging on the die casting after demolding and cooling, and preparing the aluminum alloy die casting after the cold forging is finished.

2. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: the alloy of the rare earth elements comprises a magnesium strontium alloy, an Al-Er alloy, an Al-Zr alloy and an Al-La alloy, wherein the mass ratio of the magnesium strontium alloy to the Al-Er alloy to the Al-Zr alloy to the Al-La alloy is 1: 1.2-1.5:0.8-1.2:2.2-2.5.

3. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: in the step S2, the temperature is increased from the normal temperature to the temperature of 700-750 ℃ by 15-20 ℃/min.

4. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: the heating from 700-750 ℃ to 850-900 ℃ in the step S3 is performed by raising the temperature at 5-8 ℃/min.

5. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: the temperature in the step S4 is decreased from 850-900 ℃ to 750-780 ℃ at 3-5 ℃/min.

6. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: the refining agent comprises the following raw materials in percentage by mass: KCl 25-30%, AlF₃＝40-45％、Na₂SiF₆10-15% and 15-20% of nano graphite powder.

7. The method for preparing a high-performance aluminum alloy die casting according to claim 1, wherein the method comprises the following steps: the cold forging method comprises the following steps:

s1: putting the die casting subjected to demoulding and cooling into a water bath at the temperature of 60-75 ℃, carrying out the water bath for 30-45min, taking out, putting into an oven at the temperature of 60-75 ℃, drying for 10-15min, and removing surface moisture;

s2: cooling the temperature of the oven at 5-8 ℃/min to 5-10 ℃, then taking the oven into a temperature adjusting chamber, cooling at 3-5 ℃/min to minus 5 ℃ -minus 10 ℃, preserving the temperature for 20-25min, cooling at 2-3 ℃/min to minus 20 ℃ -minus 25 ℃, preserving the temperature for 10-15min, finally cooling at 2-3 ℃/min to minus 35 ℃ -minus 40 ℃, preserving the temperature for 10-15 min;

s3: and (5) heating the temperature in the temperature adjusting room in the step S2 at the speed of 5-7 ℃/min, heating to the temperature of 15-20 ℃, keeping the temperature for 20-25min, taking out the temperature adjusting room, and finishing cold forging.

8. A high performance aluminum alloy die casting which characterized in that: the high-performance aluminum alloy die casting is prepared by the preparation method of the high-performance aluminum alloy die casting of the claims 1 to 7.

Technical Field

The invention relates to the technical field of aluminum alloy die castings, in particular to a high-performance aluminum alloy die casting and a preparation method thereof.

Background

The die casting technology is characterized in that molten metal is pressed into a precise metal die cavity at high speed by utilizing high pressure, and the molten metal is cooled and solidified under the action of pressure to form a casting. The die casting production efficiency is high, and die castings with complex shapes, accurate sizes, clear outlines, high surface quality, high strength and high hardness can be die cast, so the die casting die is wide in application and fast in development. The die-casting alloy is widely applied to the prior art. The die-casting aluminum alloy has good use performance and process performance, so the die-casting of the aluminum alloy develops rapidly, is widely applied in various industrial departments, has the use amount far higher than that of other non-ferrous alloys, and plays an extremely important role in die-casting production.

The aluminum alloy is an alloy formed by adding other elements into aluminum as a base, is the most common material in structural engineering, has the advantages of small specific gravity, good heat transfer property, good electrical conductivity, environmental protection and recycling, is widely applied to all die-casting alloys, has larger limitation on the application range due to unsatisfactory obdurability, and is particularly not suitable for parts of automobiles, motorcycles and the like with stressed and collided structures.

High-performance aluminum alloy needs to use high-quality raw materials, advanced smelting process, special refining operation, detection means matched with the refining operation and the like at the present stage, and the difficulty of the mass production process of products is high. Most manufacturers at home and abroad use the original aluminum ingot and increase correspondingly required alloy elements for production, so that the cost is high and the quality is not very stable. In addition, foreign aluminum alloy production processes, equipment and other technologies are confidential, and it is difficult to completely master the technologies at home. However, the existing die-casting aluminum alloy has the defect of unavailable die-casting performance and mechanical strength, and the application of the aluminum alloy die-casting piece in the aspect of bearing parts such as automobiles and the like is seriously influenced.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a method for preparing a high-performance aluminum alloy die casting and a die casting thereof, which solve the above problems in the background art.

The preparation method of the high-performance aluminum alloy die casting provided by the invention comprises the following steps:

s1: accurately weighing the following components in percentage by mass: 8.0-12.0% of pure silicon ingot, 3.0-5.5% of pure magnesium ingot, 1.2-2.5% of pure zinc ingot, 2.5-4.0% of pure copper ingot, 0.5-0.8% of rare earth element alloy, 0.03-0.05% of Sr0.05-0.1% of Er0.05-0.1% of pure aluminum ingot;

s2: firstly, putting aluminum, a pure silicon ingot, a pure magnesium ingot, a pure zinc ingot and a pure copper ingot into a smelting furnace, enabling the smelting furnace to be in an exhaust state, heating to 700-750 ℃, discharging argon into the smelting furnace, evacuating the air in the smelting furnace, pressurizing to 0.3-0.5MPa, and preserving heat for 20-30 min;

s3: spraying alloy of rare earth elements, Sr and Er powder into a smelting furnace in sequence, stirring and melting, heating to 850-900 ℃, and preserving heat for 25-30 min;

s4: cooling the aluminum alloy solution in the furnace body to 750-doped 780 ℃, spraying a refining agent into the furnace for refining, after refining for 5-10min, carrying out pressure relief and slagging off, after slagging off is finished, introducing argon to increase heat preservation for 15-20min, carrying out secondary slagging off, finishing refining, cooling to 650-doped 700 ℃, and detecting the aluminum alloy solution;

s5: preheating the cavity of the die to 250-300 ℃, injecting the aluminum alloy melt processed in the step S4 into the cavity of the die, wherein the flow rate of the melt at the beginning of mold filling is 0.35-0.40m/S, the casting pressure is 45-50MPa, and after the mold filling rate exceeds 50%, the flow rate of the melt is increased to 1.5-2.0m/S, and the casting pressure is 70-85MPa until the mold filling and die casting are finished;

s6: after the die casting is finished, the pressure maintaining time is 120-150s, the pressure is removed, and the die is removed and cooled after being cooled for 20-25 s;

s7: and (5) performing cold forging on the die casting after demolding and cooling, and preparing the aluminum alloy die casting after the cold forging is finished.

In some embodiments of the present invention, the alloy of rare earth elements includes magnesium strontium alloy, aluminum erbium alloy, aluminum zirconium alloy and aluminum lanthanum alloy, and the mass ratio of the magnesium strontium alloy, the aluminum erbium alloy, the aluminum zirconium alloy and the aluminum lanthanum alloy is 1: 1.2-1.5:0.8-1.2:2.2-2.5.

In other embodiments of the present invention, the heating from the normal temperature to the temperature of 700-750 ℃ in step S2 is performed by raising the temperature at 15-20 ℃/min.

In other embodiments of the present invention, the step S3 from 700-750 ℃ to 850-900 ℃ is performed by heating at a temperature of 5-8 ℃/min.

In other embodiments of the present invention, the temperature decrease from 850-900 ℃ to 750-780 ℃ in the step S4 is performed at 3-5 ℃/min.

In other embodiments of the present invention, the refining agent comprises the following raw materials by mass: KCl 25-30%, AlF₃＝40-45％、Na₂SiF₆10-15% and 15-20% of nano graphite powder.

In other embodiments of the present invention, the cold forging method is as follows:

s1: putting the die casting subjected to demoulding and cooling into a water bath at the temperature of 60-75 ℃, carrying out the water bath for 30-45min, taking out, putting into an oven at the temperature of 60-75 ℃, drying for 10-15min, and removing surface moisture;

s2: cooling the temperature of the oven at 5-8 ℃/min to 5-10 ℃, then taking the oven into a temperature adjusting chamber, cooling at 3-5 ℃/min to minus 5 ℃ -minus 10 ℃, preserving the temperature for 20-25min, cooling at 2-3 ℃/min to minus 20 ℃ -minus 25 ℃, preserving the temperature for 10-15min, finally cooling at 2-3 ℃/min to minus 35 ℃ -minus 40 ℃, preserving the temperature for 10-15 min;

s3: and (5) heating the temperature in the temperature adjusting room in the step S2 at the speed of 5-7 ℃/min, heating to the temperature of 15-20 ℃, keeping the temperature for 20-25min, taking out the temperature adjusting room, and finishing cold forging.

A high-performance aluminum alloy die casting is prepared by the preparation method of the high-performance aluminum alloy die casting.

The invention has the following good mechanical properties: the tensile strength is more than 350MPa, the elongation is more than 4.5 percent, and the hardness is more than 105 HV.

The die casting provided by the invention has the advantages of high strength, corrosion resistance, high toughness and the like.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

The invention provides a preparation method of a high-performance aluminum alloy die casting, which comprises the following steps:

s1: accurately weighing the following components in percentage by mass: 8.0% of pure silicon ingot, 3.0% of pure magnesium ingot, 1.2% of pure zinc ingot, 2.5% of pure copper ingot, 0.5% of rare earth element alloy, 0.03-0.05% of Sr0.05% of Er0.05% of pure aluminum ingot and the balance of pure aluminum ingot;

s2: firstly, putting aluminum, a pure silicon ingot, a pure magnesium ingot, a pure zinc ingot and a pure copper ingot into a smelting furnace, enabling the smelting furnace to be in an exhaust state, heating to 700 ℃ at a temperature of 15 ℃/min, discharging argon into the smelting furnace, evacuating air in the smelting furnace, pressurizing to 0.3MPa, and preserving heat for 20 min;

s3: spraying alloy of rare earth elements, Sr and Er powder into a smelting furnace in sequence, stirring and melting, heating to 850 ℃ at the temperature of 5 ℃/min, and preserving heat for 25 min;

s4: cooling the aluminum alloy solution in the furnace body to 750 ℃ at a rate of 3 ℃/min, spraying a refining agent into the furnace for refining, after refining for 5min, decompressing and slagging off, introducing argon gas after slagging off is finished, keeping the temperature for 15-20min, slagging off for the second time, finishing refining, cooling to 650 ℃, and detecting the aluminum alloy solution;

s5: preheating a cavity of a die to 250 ℃, injecting the molten aluminum alloy processed in the step S4 into the cavity of the die, wherein the flow rate of the molten aluminum alloy at the beginning of mold filling is 0.35m/S, the casting pressure is 45MPa, and after the mold filling rate exceeds 50%, the flow rate of the molten aluminum alloy is increased to 1.5m/S and the casting pressure is 70MPa until the mold filling and die casting are finished;

s6: keeping the pressure for 120s after the die casting is finished, removing the pressure, cooling for 20s, and then demolding and cooling;

s7: and (5) performing cold forging on the die casting after demolding and cooling, and preparing the aluminum alloy die casting after the cold forging is finished.

The alloy of the rare earth elements comprises a magnesium strontium alloy, an Al-Er alloy, an Al-Zr alloy and an Al-La alloy, wherein the mass ratio of the magnesium strontium alloy to the Al-Er alloy to the Al-Zr alloy to the Al-La alloy is 1: 1.2:0.8:2.2.

The refining agent comprises the following raw materials in percentage by mass: KCl 25%, AlF₃＝45％、Na₂SiF₆15% and 15% of nano graphite powder.

The cold forging method comprises the following steps:

s1: putting the die casting subjected to demoulding and cooling into a water bath at 60 ℃, carrying out the water bath for 30min, taking out, putting into a drying oven at 60 ℃, drying for 10min, and removing surface moisture;

s2: cooling the temperature of the oven at 5 ℃/min, cooling to 5 ℃, then taking the oven into a temperature adjusting chamber, cooling at 3 ℃/min, cooling to minus 5 ℃, preserving the temperature for 20min, cooling at 2 ℃/min, cooling to minus 20 ℃, preserving the temperature for 10min, finally cooling at 2 ℃/min, cooling to minus 35 ℃, and preserving the temperature for 10 min;

s3: and (5) heating the temperature in the temperature adjusting chamber in the step S2 at a speed of 5 ℃/min, heating to 15 ℃, keeping the temperature for 20min, taking out the temperature adjusting chamber, and finishing cold forging to obtain the die casting.

Example 2

The invention provides a preparation method of a high-performance aluminum alloy die casting, which comprises the following steps:

s1: accurately weighing the following components in percentage by mass: 12.0% of pure silicon ingot, 5.5% of pure magnesium ingot, 2.5% of pure zinc ingot, 4.0% of pure copper ingot, 0.8% of rare earth element alloy, 0.05% of Sr0.1% of rare earth element alloy and the balance of pure aluminum ingot;

s2: firstly, putting aluminum, a pure silicon ingot, a pure magnesium ingot, a pure zinc ingot and a pure copper ingot into a smelting furnace, enabling the smelting furnace to be in an exhaust state, heating to 750 ℃ at a temperature of 20 ℃/min, discharging argon into the smelting furnace, evacuating air in the smelting furnace, pressurizing to 0.5MPa, and preserving heat for 30 min;

s3: spraying alloy of rare earth elements, Sr and Er powder into a smelting furnace in sequence, stirring and melting, heating to 900 ℃ at the speed of 8 ℃/min, and preserving heat for 30 min;

s4: cooling the aluminum alloy solution in the furnace body to 780 ℃ at a speed of 5 ℃/min, spraying a refining agent into the furnace for refining, after refining for 10min, decompressing and slagging off, introducing argon gas to increase the temperature for 20min after slagging off is finished, slagging off for the second time, finishing refining, cooling to 700 ℃, and detecting the aluminum alloy solution;

s5: preheating a cavity of a die to 300 ℃, injecting the molten aluminum alloy processed in the step S4 into the cavity of the die, wherein the flow rate of the molten aluminum alloy at the beginning of mold filling is 0.40m/S, the casting pressure is 50MPa, and after the mold filling rate exceeds 50%, the flow rate of the molten aluminum alloy is increased to 2.0m/S and the casting pressure is 85MPa until the mold filling and die casting are finished;

s6: keeping the pressure for 150s after the die casting is finished, removing the pressure, cooling for 25s, and then demolding and cooling;

s7: and (5) performing cold forging on the die casting after demolding and cooling, and preparing the aluminum alloy die casting after the cold forging is finished.

The alloy of the rare earth elements comprises a magnesium strontium alloy, an Al-Er alloy, an Al-Zr alloy and an Al-La alloy, wherein the mass ratio of the magnesium strontium alloy to the Al-Er alloy to the Al-Zr alloy to the Al-La alloy is 1: 1.5:1.2:2.5.

The refining agent comprises the following raw materials in percentage by mass: KCl 30%, AlF₃＝40％、Na₂SiF₆10% and 20% of nano graphite powder.

The cold forging method comprises the following steps:

s1: putting the die casting subjected to demoulding and cooling into a water bath at 75 ℃, carrying out the water bath for 45min, taking out, putting into a drying oven at 75 ℃, drying for 15min, and removing surface moisture;

s2: cooling the temperature of the oven at 8 ℃/min, cooling to 10 ℃, then taking the oven into a temperature adjusting chamber, cooling at 5 ℃/min, cooling to minus 10 ℃ below zero, preserving the temperature for 20-25min, cooling at 3 ℃/min, cooling to minus 25 ℃, preserving the temperature for 15min, finally cooling at 3 ℃/min, cooling to minus 40 ℃ and preserving the temperature for 15 min;

s3: and (5) heating the temperature in the temperature adjusting chamber in the step (S2) at the speed of 7 ℃/min, heating to 20 ℃, keeping the temperature for 20-25min, taking out the temperature adjusting chamber, and finishing cold forging to obtain the die casting.

Example 3

The invention provides a preparation method of a high-performance aluminum alloy die casting, which comprises the following steps:

s1: accurately weighing the following components in percentage by mass: 10.0% of pure silicon ingot, 4.5% of pure magnesium ingot, 2.0% of pure zinc ingot, 3.0% of pure copper ingot, 0.7% of rare earth element alloy, 0.04% of Sr0.08%, and the balance of pure aluminum ingot;

s2: firstly, putting aluminum, a pure silicon ingot, a pure magnesium ingot, a pure zinc ingot and a pure copper ingot into a smelting furnace, enabling the smelting furnace to be in an exhaust state, heating to 720 ℃ at a temperature of 18 ℃/min, discharging argon into the smelting furnace, evacuating air in the smelting furnace, pressurizing to 0.4MPa, and preserving heat for 25 min;

s3: spraying alloy of rare earth elements, Sr and Er powder into a smelting furnace in sequence, stirring and melting, heating to 870 ℃ at the temperature of 6 ℃/min, and preserving heat for 28 min;

s4: cooling the aluminum alloy solution in the furnace body to 765 ℃ at a speed of 4 ℃/min, spraying a refining agent into the furnace, refining, after refining for 8min, decompressing and slagging off, introducing argon gas after slagging off is finished, increasing the temperature for 15-20min, slagging off for the second time, finishing refining, cooling to 670 ℃, and detecting the aluminum alloy solution;

s5: preheating a cavity of the die to 280 ℃, injecting the molten aluminum alloy processed in the step S4 into the cavity of the die, wherein the flow rate of the molten aluminum alloy at the beginning of mold filling is 0.38m/S, the casting pressure is 48MPa, and after the mold filling rate exceeds 50%, the flow rate of the molten aluminum alloy is increased to 1.7m/S and the casting pressure is 78MPa until the mold filling and die casting are finished;

s6: keeping the pressure for 135s after the die casting is finished, removing the pressure, cooling for 23s, and then demolding and cooling;

s7: and (5) performing cold forging on the die casting after demolding and cooling, and preparing the aluminum alloy die casting after the cold forging is finished.

The alloy of the rare earth elements comprises a magnesium strontium alloy, an Al-Er alloy, an Al-Zr alloy and an Al-La alloy, wherein the mass ratio of the magnesium strontium alloy to the Al-Er alloy to the Al-Zr alloy to the Al-La alloy is 1: 1.3:1.0:2.3.

The refining agent comprises the following raw materials in percentage by mass: KCl 28%, AlF₃＝42％、Na₂SiF₆12% and 18% of nano graphite powder.

The cold forging method comprises the following steps:

s1: putting the die casting subjected to demoulding and cooling into a water bath at 68 ℃, carrying out the water bath for 38min, taking out, putting into an oven at 68 ℃, drying for 12min, and removing surface moisture;

s2: cooling the temperature of the oven at 6 ℃/min to 8 ℃, then taking the oven into a temperature adjusting chamber, cooling at 4 ℃/min to 8 ℃ below zero, keeping the temperature for 22min, cooling at 2.5 ℃/min to 23 ℃ below zero, keeping the temperature for 12min, finally cooling at 2.5 ℃/min to 38 ℃ below zero, and keeping the temperature for 12 min;

s3: and (5) heating the temperature in the temperature adjusting chamber in the step (S2) at 6 ℃/min, heating to 18 ℃, keeping the temperature for 22min, taking out the temperature adjusting chamber, and finishing cold forging to obtain the die casting.

The examples 1-3 were subjected to performance tests in comparison with the commercially available die-cast parts of comparative examples 1-2, and the results are shown in the following table:

	example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Tensile strength/MPa	351	358	353	332	328
Yield strength/MPa	250	248	242	235	231
						Elongation%	7.88	7.35	7.95	7.45	7.34
Elongation percentage	4.56	4.62	4.58	4.27	4.38
						hardness/HV	110	108	113	98	95

As can be seen from the table above, the die casting has better tensile strength, yield strength, elongation and hardness than the die casting products purchased in the market, has better physical properties, and also has the advantages of corrosion resistance, high toughness and the like.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.