阅读说明：本技术 高性能铝合金汽车零部件制备方法 (Preparation method of high-performance aluminum alloy automobile parts ) 是由 田跃文 朱立群 陆洋峰 张峰 张显东 夏恩帅 纪伟 于 2019-08-29 设计创作，主要内容包括：本发明高性能铝合金汽车零部件制备方法,步骤如下：原材料准备,以百分比计：Si 9.0-10％；Mg 0.051～0.54％；Fe≤1.5％；Cu 2.5-4.0％；Mn≤0.56％,Ni≤0.56％；Zn≤1.3％；Ti≤0.26％；Cr≤0.16％；银Cr≤0.1％；石墨Cr≤0.16％；碳化硅Cr≤0.16％,以及占据余量的Al；变质处理；电磁搅拌；注入氧气；压铸零件固化；脱模具成型。(the preparation method of the high-performance aluminum alloy automobile part comprises the following steps: preparing raw materials, by percentage: 9.0 to 10 percent of Si; 0.051 to 0.54 percent of Mg; fe is less than or equal to 1.5 percent; 2.5 to 4.0 percent of Cu; mn is less than or equal to 0.56 percent, and Ni is less than or equal to 0.56 percent; zn is less than or equal to 1.3 percent; ti is less than or equal to 0.26 percent; cr is less than or equal to 0.16 percent; silver Cr is less than or equal to 0.1 percent; graphite Cr is less than or equal to 0.16 percent; the silicon carbide Cr is less than or equal to 0.16 percent, and the balance of Al is occupied; modification treatment; electromagnetic stirring; injecting oxygen; curing the die-casting part; and (5) forming by using a demolding tool.)

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

1) preparing raw materials, by percentage:

9.0 to 10 percent of Si; 0.051 to 0.54 percent of Mg; fe is less than or equal to 1.5 percent; 2.5 to 4.0 percent of Cu; mn is less than or equal to 0.56 percent, and Ni is less than or equal to 0.56 percent; zn is less than or equal to 1.3 percent; ti is less than or equal to 0.26 percent; cr is less than or equal to 0.16 percent; silver Cr is less than or equal to 0.1 percent; graphite Cr is less than or equal to 0.16 percent; the silicon carbide Cr is less than or equal to 0.16 percent, and the balance of Al is occupied;

2) Melting the raw materials, heating to 720-750 ℃, adding a modifier, heating to 810 ℃ for modification treatment, wherein the addition amount of the modifier is 0.7 percent of the total weight of the ingredients, obtaining molten metal liquid, and then preserving heat;

3) Performing electromagnetic stirring on the molten metal liquid, wherein the electromagnetic stirring current is 30-45A, the frequency is 30-35Hz, and performing circumferential stirring for 3-5 minutes to obtain material liquid;

4) closing the die to form a cavity and a pouring gate, injecting oxygen into an injection chamber and the cavity of the die-casting die through a gas injection hole arranged on the downstream side of a pouring gate, removing air in the injection chamber and the cavity, cleaning the injection chamber and the cavity, and injecting the oxygen for 10-15 seconds at the pressure of 0.8-1.2 MPa;

5) Stopping injecting oxygen into the die cavity and the injection chamber and vacuumizing the die cavity and the injection chamber from the top of the die-casting die; injecting an alloy melt into the injection chamber from the sprue gate, controlling the temperature of the alloy melt to be 690-710 ℃ during injection, pressing a punch into the injection chamber at the speed of 0.2-0.3 m/s after injection is finished, enabling the alloy melt in the injection chamber to enter a cavity through a pouring gate, stopping vacuumizing and linearly accelerating the punch when the punch advances to one third of the volume of the injection chamber, accelerating the pressing speed of the punch to 3-4 m/s when the punch advances to two thirds of the volume of the injection chamber, and keeping the pressure of the punch to be 12-15MPa after the punch is pressed until a die-cast part is solidified;

6) and (5) forming by using a demolding tool.

2. The method for preparing the high-performance aluminum alloy automobile part according to claim 1, wherein the method comprises the following steps: and 3) introducing inert gas for protection.

3. The method for preparing the high-performance aluminum alloy automobile part according to claim 2, wherein the method comprises the following steps: argon with the purity of 99.99 percent is selected as the inert gas in the step 3).

4. The method for preparing the high-performance aluminum alloy automobile part according to claim 3, wherein the method comprises the following steps: and 4) stopping die assembly when the gap between the parting surfaces of the dies is 20 mm.

Technical Field

The invention relates to the technical field of die-casting molding, and particularly discloses a preparation method of a high-performance aluminum alloy automobile part.

Background

Die casting is called casting for short, and is a precision forming technology for metal parts close to the final shape and size, and the final product is a die casting. The essence of the method is that under the action of high pressure, liquid metal is filled into a die cavity at high speed, and is formed and solidified under the action of pressure, so that a die casting with clear outline and smooth surface is obtained. In the non-ferrous metal casting industry, die casting is an important casting method. In recent years, light alloys mainly containing magnesium and aluminum have gained importance in the die casting industry, and aluminum alloy castings obtained by die casting account for about six components of the total amount of lead alloy castings.

In recent years, with the acceleration of weight reduction of automobiles, the performance requirements of parts of automobiles are more severe, such as high yield strength required in the design of automobile parts, high elongation, excellent impact toughness, good wear resistance and fatigue performance required in deformation. At present, automobile materials in domestic and foreign markets use aluminum alloys on a large scale, but common aluminum alloys cannot meet the requirements of the modern automobile industry, for example, the aluminum magnesium materials in the current markets have the defects of poor mechanical property, poor cutting processability and the like, most of the aluminum alloys are prepared by heat treatment, the cost consumption is high, and higher requirements are provided for the alloy materials and the preparation process thereof.

Therefore, it is necessary to provide a method for preparing high-performance aluminum alloy automobile parts to solve the above problems.

Disclosure of Invention

the invention aims to provide a preparation method of a high-performance aluminum alloy automobile part.

The technical scheme is as follows:

a preparation method of a high-performance aluminum alloy automobile part comprises the following steps:

1) preparing raw materials, by percentage:

9.0 to 10 percent of Si; 0.051 to 0.54 percent of Mg; fe is less than or equal to 1.5 percent; 2.5 to 4.0 percent of Cu; mn is less than or equal to 0.56 percent, and Ni is less than or equal to 0.56 percent; zn is less than or equal to 1.3 percent; ti is less than or equal to 0.26 percent; cr is less than or equal to 0.16 percent; silver Cr is less than or equal to 0.1 percent; graphite Cr is less than or equal to 0.16 percent; the silicon carbide Cr is less than or equal to 0.16 percent, and the balance of Al is occupied;

2) melting the raw materials, heating to 720-750 ℃, adding a modifier, heating to 810 ℃ for modification treatment, wherein the addition amount of the modifier is 0.7 percent of the total weight of the ingredients, obtaining molten metal liquid, and then preserving heat;

3) performing electromagnetic stirring on the molten metal liquid, wherein the electromagnetic stirring current is 30-45A, the frequency is 30-35Hz, and performing circumferential stirring for 3-5 minutes to obtain material liquid;

4) Closing the die to form a cavity and a pouring gate, injecting oxygen into an injection chamber and the cavity of the die-casting die through a gas injection hole arranged on the downstream side of a pouring gate, removing air in the injection chamber and the cavity, cleaning the injection chamber and the cavity, and injecting the oxygen for 10-15 seconds at the pressure of 0.8-1.2 MPa;

5) stopping injecting oxygen into the die cavity and the injection chamber and vacuumizing the die cavity and the injection chamber from the top of the die-casting die; injecting an alloy melt into the injection chamber from the sprue gate, controlling the temperature of the alloy melt to be 690-710 ℃ during injection, pressing a punch into the injection chamber at the speed of 0.2-0.3 m/s after injection is finished, enabling the alloy melt in the injection chamber to enter a cavity through a pouring gate, stopping vacuumizing and linearly accelerating the punch when the punch advances to one third of the volume of the injection chamber, accelerating the pressing speed of the punch to 3-4 m/s when the punch advances to two thirds of the volume of the injection chamber, and keeping the pressure of the punch to be 12-15MPa after the punch is pressed until a die-cast part is solidified;

6) and (5) forming by using a demolding tool.

further, in the step 3), inert gas is introduced for protection.

further, the inert gas in the step 3) is argon with the purity of 99.99 percent.

Further, in the step 4), when the gap between the parting surfaces of the molds is 20 mm, the mold closing is stopped.

compared with the prior art, the invention greatly reduces the development cost, has high product percent of pass, has better void ratio than the common process design, has stable product mold filling process and greatly reduces the defective rate of air holes inside the die casting, not only improves the quality, but also reduces the labor intensity.

Detailed Description