Heat treatment-free die-casting aluminum alloy based on pure aluminum alloy and preparation method and application thereof

Abstract

The invention relates to the technical field of aluminum alloy materials, and discloses a heat treatment-free die-casting aluminum alloy based on pure aluminum alloy, which is characterized by comprising alloy components, wherein the alloy components include silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and composite materials. The alloy component element ratios are silicon (Si) 6.0-8.0%, magnesium (Mg) 0.3-0.6%, copper (Cu) 0.1-0.3%, iron (Fe) ≤0.3%, manganese (Mn) ≤0.1%, zinc (Zn) ≤0.1%, and titanium (Ti) 0.05-0.15%, and the rare earth element is cerium (Ce), and the proportion is 0.01-0.1%. The heat-treatment-free die-cast aluminum alloy based on pure aluminum alloy and its preparation method and application optimize the alloy composition and preparation process, introduce rare earth elements, improve the microstructure and mechanical properties of the material, and add ceramic particles to achieve composite strengthening, thereby greatly improving the hardness and wear resistance of the material without sacrificing ductility, thereby avoiding the complex heat treatment process required for traditional die-casting aluminum alloys.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy materials, and in particular to a heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy, and a preparation method and application thereof. Background Art

[0002] Aluminum alloys have been widely used in modern industry due to their low density, high specific strength, good thermal conductivity and electrical conductivity, excellent corrosion resistance and recyclability, especially in the fields of automobiles, aerospace, electronic communications, construction, etc. Aluminum alloys have become one of the indispensable materials.

[0003] However, traditional aluminum alloys usually need to undergo heat treatment processes such as solution treatment and aging treatment after die-casting to improve their mechanical properties. These heat treatment processes are not only time-consuming and energy-consuming, but also increase production costs, which may also affect the final dimensional accuracy and surface quality of the product. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a heat-treatment-free die-cast aluminum alloy based on pure aluminum alloy and its preparation method and application, which has the advantages of avoiding the complicated heat treatment process required for traditional die-casting aluminum alloys, and solves the problems mentioned in the above background technology.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy, comprising alloy components, wherein the alloy components include silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and a composite material. The alloy component element ratio is silicon (Si) 6.0-8.0%, magnesium (Mg) 0.3-0.6%, copper (Cu) 0.1-0.3%, iron (Fe) ≤0.3%, manganese (Mn) ≤0.1%, zinc (Zn) ≤0.1%, and titanium (Ti) 0.05-0.15%, the rare earth element is cerium (Ce), accounting for 0.01-0.1%, the ceramic particles are silicon carbide (SiC), accounting for 0.1-1%, and the rest are aluminum Al and a small amount of other trace elements. The composite material is carbon fiber, and the addition amount of the carbon fiber is 5-10%.

[0008] A method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy comprises the following steps:

[0009] Ⅰ: Alloy composition design;

[0010] Ⅱ: Raw materials preparation and selection;

[0011] III: smelting and purification;

[0012] IV: Filtration and pouring;

[0013] V: Demolding and post-processing.

[0014] Preferably, the alloy components are silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and the rest are aluminum Al and a small amount of other trace elements.

[0015] Preferably, the raw material is a high-purity aluminum ingot (aluminum above 99.7%) as the base material, which is pretreated to remove the oxide layer and impurities on the surface.

[0016] Preferably, in step III, a medium frequency induction furnace is used for smelting, the smelting furnace is started, and the temperature is gradually increased to 750-780°C to completely melt the aluminum ingot. After the aluminum ingot is basically melted, alloy elements, rare earth elements and composite materials are added in sequence according to a predetermined ratio and stirred. After smelting, an appropriate amount of chloride salt is added to the furnace to remove surface oxides and inclusions. Argon gas is used for degassing, and argon gas is evenly blown into the molten alloy liquid through a nozzle. The rising effect of argon bubbles is used to take away hydrogen and other gases dissolved in the alloy liquid. The degassing time is 10-15 minutes.

[0017] Preferably, electromagnetic stirring is used in step III to stir the alloy liquid evenly and improve its purity. After degassing, the alloy liquid is allowed to stand in the furnace for 10-15 minutes, and the melting temperature is maintained in the range of 750-780°C.

[0018] Preferably, in step IV, the alloy liquid is filtered using a foam ceramic filter before pouring, the mold is preheated to 200-250°C, the purified alloy liquid is injected into the mold at high speed (1.5-2.5m / s) and high pressure, and then water cooling is used to accelerate the cooling process. The spray deposition rapid solidification technology is used to transform the alloy from liquid to solid in a short time.

[0019] Preferably, in step IV, after the casting is completely cooled, the casting is taken out from the mold, and the casting is subjected to deburring, grinding, and polishing surface treatment as needed, and T6 aging treatment can be selectively performed. After die-casting, the casting is subjected to ultrasonic treatment, and the cavitation effect of ultrasound is used to eliminate internal stress and improve the microstructure of the material. Laser surface treatment technology is used to enhance surface properties and improve surface hardness, wear resistance and corrosion resistance.

[0020] A heat treatment-free die-casting aluminum alloy based on pure aluminum alloy is used in body structural parts and engine parts in the automobile manufacturing industry.

[0021] Compared with the prior art, the present invention provides a heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy and a preparation method and application thereof, which have the following beneficial effects:

[0022] The heat-treatment-free die-cast aluminum alloy based on pure aluminum alloy and its preparation method and application optimize the alloy composition and preparation process, introduce rare earth elements, improve the microstructure and mechanical properties of the material, and add ceramic particles to achieve composite strengthening, thereby greatly improving the hardness and wear resistance of the material without sacrificing ductility, thereby avoiding the complex heat treatment process required for traditional die-casting aluminum alloys. DETAILED DESCRIPTION

[0023] Example 1

[0024] A heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy comprises alloy components, wherein the alloy components include silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and a composite material. The alloy component element ratios are silicon (Si) 6.0%, magnesium (Mg) 0.3%, copper (Cu) 0.1%, iron (Fe) ≤0.15%, manganese (Mn) ≤0.05%, zinc (Zn) ≤0.05%, and titanium (Ti) 0.05%. The rare earth element is cerium (Ce), which accounts for 0.01%, and the ceramic particle silicon carbide (SiC) accounts for 0.1%. The rest is aluminum Al and a small amount of other trace elements. The composite material is carbon fiber, and the addition amount of the carbon fiber is 5%.

[0025] A method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy comprises the following steps:

[0026] S1. Raw material preparation and selection: Select high-purity industrial pure aluminum ingots (more than 99.7%), and prepare corresponding master alloys according to alloy composition design, such as silicon aluminum alloy, magnesium aluminum alloy, copper aluminum alloy, etc.;

[0027] S2. Pretreatment: remove oil stains, oxide layers and impurities on the surface of aluminum ingots and master alloys, and accurately weigh each raw material according to the predetermined alloy composition ratio;

[0028] S3, smelting: prepare a medium frequency induction furnace, put the pretreated aluminum ingot into the smelting furnace, start the smelting furnace, gradually increase the temperature to 750°C, and completely melt the aluminum ingot. When the aluminum ingot is basically melted, add silicon, magnesium, copper and other intermediate alloys in a predetermined proportion, and stir by electromagnetic stirring;

[0029] S4, slag removal: add an appropriate amount of chloride salt to the smelting furnace, remove the oxides and inclusions on the surface through chemical reaction, and use the slag removal tool to clean the slag floating on the surface;

[0030] S5. Degassing: Blow argon gas evenly into the molten alloy liquid through the nozzle, and use the rising effect of argon bubbles to take away the hydrogen and other gases dissolved in the alloy liquid. The degassing time is 10 minutes;

[0031] S6. Standing: The degassed alloy liquid is allowed to stand in the melting furnace for 10 minutes, and the melting temperature is maintained within the range of 750°C;

[0032] S7, Filtration: Before pouring, use a foam ceramic filter to filter the alloy liquid. Install the filter in the ladle or launder to ensure that the alloy liquid is filtered before pouring;

[0033] S8, preheating: preheat the mold to 200°C;

[0034] S9, pouring: inject the purified alloy liquid into the mold at a high speed of 1.5m / s and high pressure, and maintain the pressure for a certain period of time to allow the alloy liquid to fully solidify in the mold. The holding time is 10 seconds;

[0035] S10, Cooling: Use water cooling to accelerate the cooling process and ensure uniform cooling of the casting;

[0036] S11, demoulding: after the casting is completely cooled, remove the casting from the mold;

[0037] S12. Surface treatment: remove burrs and flash on the surface of castings, use sandpaper or grinding wheel to grind the surface of castings to improve surface finish, polish the parts that require high finish, and perform ultrasonic treatment immediately after die casting to eliminate internal stress and improve the microstructure of the material. The treatment time is generally 10-30 minutes, and the ultrasonic frequency is generally 20-40kHz. Use laser surface treatment technology to enhance surface properties, improve surface hardness, wear resistance and corrosion resistance, the laser power is 1-5kW, and the scanning speed is 1-10m / min.

[0038] Example 2

[0039] A heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy comprises alloy components, wherein the alloy components include silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and a composite material. The alloy component element ratios are silicon (Si) 8.0%, magnesium (Mg) 0.6%, copper (Cu) 0.3%, iron (Fe) ≤0.3%, manganese (Mn) ≤0.1%, zinc (Zn) ≤0.1%, and titanium (Ti) 0.15%. The rare earth element is cerium (Ce), accounting for 0.1%, and the ceramic particle silicon carbide (SiC) accounts for 1%, and the rest is aluminum Al and a small amount of other trace elements. The composite material is carbon fiber, and the addition amount of the carbon fiber is 10%.

[0040] A method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy comprises the following steps:

[0041] S1. Raw material preparation and selection: Select high-purity industrial pure aluminum ingots (more than 99.7%), and prepare corresponding master alloys according to alloy composition design, such as silicon aluminum alloy, magnesium aluminum alloy, copper aluminum alloy, etc.;

[0042] S2. Pretreatment: remove oil stains, oxide layers and impurities on the surface of aluminum ingots and master alloys, and accurately weigh each raw material according to the predetermined alloy composition ratio;

[0043] S3, smelting: prepare a medium frequency induction furnace, put the pretreated aluminum ingot into the smelting furnace, start the smelting furnace, gradually increase the temperature to 750°C, and completely melt the aluminum ingot. When the aluminum ingot is basically melted, add silicon, magnesium, copper and other intermediate alloys in a predetermined proportion, and stir by electromagnetic stirring;

[0044] S4, slag removal: add an appropriate amount of chloride salt to the smelting furnace, remove the oxides and inclusions on the surface through chemical reaction, and use the slag removal tool to clean the slag floating on the surface;

[0045] S5. Degassing: Blow argon gas evenly into the molten alloy liquid through the nozzle, and use the rising effect of argon bubbles to take away the hydrogen and other gases dissolved in the alloy liquid. The degassing time is 10 minutes;

[0046] S6. Standing: The degassed alloy liquid is allowed to stand in the melting furnace for 10 minutes, and the melting temperature is maintained within the range of 750°C;

[0047] S7, Filtration: Before pouring, use a foam ceramic filter to filter the alloy liquid. Install the filter in the ladle or launder to ensure that the alloy liquid is filtered before pouring;

[0048] S8, preheating: preheat the mold to 200°C;

[0049] S9, pouring: inject the purified alloy liquid into the mold at a high speed of 1.5m / s and high pressure, and maintain the pressure for a certain period of time to allow the alloy liquid to fully solidify in the mold. The holding time is 10 seconds;

[0050] S10, Cooling: Use water cooling to accelerate the cooling process and ensure uniform cooling of the casting;

[0051] S11, demoulding: after the casting is completely cooled, remove the casting from the mold;

[0052] S12. Surface treatment: remove burrs and flash on the surface of castings, use sandpaper or grinding wheel to grind the surface of castings to improve surface finish, polish the parts that require high finish, and perform ultrasonic treatment immediately after die casting to eliminate internal stress and improve the microstructure of the material. The treatment time is generally 10-30 minutes, and the ultrasonic frequency is generally 20-40kHz. Use laser surface treatment technology to enhance surface properties, improve surface hardness, wear resistance and corrosion resistance, the laser power is 1-5kW, and the scanning speed is 1-10m / min.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy, characterized in that: The invention comprises alloy components, wherein the alloy components include silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and a composite material. The proportion of the alloy components is 6.0-8.0% of silicon (Si), 0.3-0.6% of magnesium (Mg), 0.1-0.3% of copper (Cu), ≤0.3% of iron (Fe), ≤0.1% of manganese (Mn), ≤0.1% of zinc (Zn), and 0.05-0.15% of titanium (Ti). The rare earth element is cerium (Ce), accounting for 0.01-0.1% of the proportion. The ceramic particles are silicon carbide (SiC), accounting for 0.1-1% of the proportion. The rest are aluminum Al and a small amount of other trace elements. The composite material is carbon fiber, and the addition amount of the carbon fiber is 5-10%.

2. The method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy according to claim 1, characterized in that: The following steps are involved: Ⅰ: Alloy composition design; Ⅱ: Raw materials preparation and selection; III: smelting and purification; IV: Filtration and pouring; V: Demolding and post-processing.

3. The method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy according to claim 2, characterized in that: The alloy components are silicon (Si), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), titanium (Ti), rare earth elements, ceramic particles, and the rest are aluminum Al and a small amount of other trace elements.

4. The method for preparing a heat-treatment-free die-casting aluminum alloy based on a pure aluminum alloy according to claim 2, characterized in that: The raw material is a high-purity aluminum ingot (aluminum above 99.7%) as a base material, which is pretreated to remove the oxide layer and impurities on the surface.

5. The method for preparing heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy according to claim 2, characterized in that: In step III, a medium frequency induction furnace is used for smelting. The smelting furnace is started and the temperature is gradually increased to 750-780°C to completely melt the aluminum ingot. After the aluminum ingot is basically melted, alloy elements, rare earth elements and composite materials are added in sequence according to a predetermined ratio and stirred. After smelting, an appropriate amount of chloride salt is added to the furnace to remove surface oxides and inclusions. Argon gas is used for degassing. Argon gas is evenly blown into the molten alloy liquid through a nozzle, and the rising effect of argon bubbles is used to take away hydrogen and other gases dissolved in the alloy liquid. The degassing time is 10-15 minutes.

6. The method for preparing heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy according to claim 5, characterized in that: In step III, electromagnetic stirring is used to stir the alloy liquid so that it is evenly mixed and its purity is improved. After degassing, the alloy liquid is allowed to stand in the furnace for 10-15 minutes, and the melting temperature is maintained in the range of 750-780°C.

7. The method for preparing heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy according to claim 2, characterized in that: In step IV, the alloy liquid is filtered using a foam ceramic filter before pouring, the mold is preheated to 200-250°C, and the purified alloy liquid is injected into the mold at high speed (1.5-2.5m / s) and high pressure, and then water cooling is used to accelerate the cooling process. The spray deposition rapid solidification technology is used to transform the alloy from liquid to solid in a short time.

8. The method for preparing heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy according to claim 2, characterized in that: In step IV, after the casting is completely cooled, the casting is taken out from the mold, and the casting is deburred, ground, and polished as needed, and T6 aging treatment can be selectively performed. After die-casting, the casting is ultrasonically treated to eliminate internal stress by using the cavitation effect of ultrasound, improve the microstructure of the material, and use laser surface treatment technology to enhance surface properties and improve surface hardness, wear resistance and corrosion resistance.

9. An application method of heat-treatment-free die-casting aluminum alloy based on pure aluminum alloy, characterized in that: The heat-treatment-free die-cast aluminum alloy based on pure aluminum alloy as described in claim 1 is applied to body structural parts and engine parts in the automobile manufacturing industry.