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US-12623280-B2 - Die-casting aluminum alloy without heat-treatment and preparation method and application thereof

US12623280B2US 12623280 B2US12623280 B2US 12623280B2US-12623280-B2

Abstract

A die-casting aluminum alloy without heat-treatment and a preparation method and application thereof. Based on a total weight of the die-casting aluminum alloy, the die-casting aluminum alloy includes: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.8 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.

Inventors

  • Xinxing Wu
  • Dong Yang
  • Yongchang BAI

Assignees

  • XIAOMI EV TECHNOLOGY CO., LTD.

Dates

Publication Date
20260512
Application Date
20230530
Priority Date
20221031

Claims (20)

  1. 1 . An aluminum alloy, based on total weight of the aluminum alloy, the aluminum alloy comprising: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.8wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.8 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  2. 2 . The aluminum alloy of claim 1 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 0.9 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.65 to 0.75 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  3. 3 . The aluminum alloy of claim 1 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.75 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  4. 4 . The aluminum alloy of claim 1 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 0.9 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.65 to 0.69 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  5. 5 . The aluminum alloy of claim 1 , further comprising 0.05 to 0.15 wt % of Sn based on the total weight of the aluminum alloy.
  6. 6 . The aluminum alloy of claim 5 , wherein in the aluminum alloy, mass ratio of Sn to Fe is not greater than 1.0, mass ratio of Mn to Fe is not less than 3.0, and mass ratio of Ce to La is not less than 2.0.
  7. 7 . The aluminum alloy of claim 1 , wherein the aluminum alloy has an ultimate tensile strength of 300 to 350 MPa, a yield strength of 150 to 180 MPa, an elongation at break of 11.0 to 16.0%, and a bending angle of 23.0 to 27.0° at a section thickness of 3.2 mm.
  8. 8 . A method for preparing an aluminum alloy of claim 1 , comprising: melting aluminum in a smelting furnace, adding thereto silicon, magnesium, a Cu raw material, a Fe raw material and an Mn raw material, and performing first smelting to obtain a first melt; transferring the first melt to a converter after the first melt is cooled down, adding a first material at a bottom of the first melt, and performing second smelting and first degassing, refining and deslagging to obtain a second melt; transferring the second melt to a holding furnace for component testing after the second melt is cooled down, and performing high-pressure die-casting on the second melt qualified after the component testing to obtain the aluminum alloy; wherein the first material comprises a Ti raw material, a Sr raw material, a Ce raw material, a La raw material, a Zr raw material and a Sn raw material, or the first material comprises the Ti raw material, the Sr raw material, the Ce raw material, the La raw material and the Zr raw material.
  9. 9 . The method of claim 8 , wherein the Cu raw material is an Al—Cu alloy; the Fe raw material is an Al—Fe alloy; the Mn raw material is an Al—Mn alloy; the Ti raw material is an Al—Ti alloy; the Sr raw material is an Al—Sr alloy; the Ce raw material is an Al—Ce alloy; the La raw material is an Al—La alloy; the Zr raw material is an Al—Zr alloy; and the Sn raw material is an Al—Sn alloy.
  10. 10 . The method of claim 9 , wherein the Al—Cu alloy is an Al-50Cu master alloy; the Al—Fe alloy is an Al-5Fe master alloy; the Al—Mn alloy is an Al-20Mn master alloy; the Al—Ti alloy is an Al-5Ti master alloy; the Al—Sr alloy is an Al-5Sr master alloy; the Al—Ce alloy is an Al-10Ce master alloy; the Al—La alloy is an Al-10La master alloy; the Al—Zr alloy is an Al-5Zr master alloy; and the Al—Sn alloy is an Al-12Sn master alloy.
  11. 11 . The method of claim 9 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.75 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  12. 12 . The method of claim 9 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 0.9 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.65 to 0.69 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  13. 13 . The method of claim 8 , wherein a smelting temperature of the smelting furnace is 740 to 760° C.; a transfer temperature of the converter is 710 to 730° C.; and a holding temperature of the holding furnace is 690 to 710° C.
  14. 14 . The method of claim 8 , wherein the first degassing, refining and deslagging comprises: adding refining agent powders into a furnace body of the converter under an atmosphere of an inert gas or nitrogen, the inert gas being argon.
  15. 15 . The method of claim 8 , wherein a condition of the high-pressure comprises: a pressure of 26 to 70 MPa, an injection speed of 5.5 to 7.0 m/s, and a die casting-temperature of 690 to 710° C.
  16. 16 . The method of claims 8 , further comprising: drying the aluminum, the silicon, the magnesium, the Cu raw material, the Fe raw material, the Mn raw material, the Ti raw material, the Sr raw material, the Ce raw material, the La raw material, the Zr raw material and the Sn raw material before the melting or the smelting steps, wherein the drying is performed at a temperature of 150 to 200° C.
  17. 17 . A structural part of an automobile body, comprising an aluminum alloy, wherein the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.8 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  18. 18 . The structural part of the automobile body of claim 17 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 0.9 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.65 to 0.75 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  19. 19 . The structural part of the automobile body of claim 17 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.75 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.
  20. 20 . The structural part of the automobile body of claim 17 , wherein based on the total weight of the aluminum alloy, the aluminum alloy comprises: 6.0 to 8.0 wt % of Si; 0.3 to 0.9 wt % of Mg; 0.4 to 0.58 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.65 to 0.69 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims priority to Chinese Patent Application No. 202211350885.9, filed Oct. 31, 2022, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to the technical field of aluminum alloys, and more particularly, to a die-casting aluminum alloy without heat-treatment and a preparation method and application thereof. BACKGROUND Reducing the weight of automobile is of great significance for promoting energy saving and emission reduction. Aluminum alloy has a high specific strength and is an ideal material for realizing the lightweight of automobiles. As the amount of aluminum alloys used in automobiles increases, the splicing process of structural body parts has become more difficult and less efficient. The development of high-performance die-casting aluminum alloys and the realization of integrated die-casting of structural body parts may break through this bottleneck. In making die-casting aluminum alloys for automotive structural body parts, the subsequent heat treatment may cause dimensional deformation and surface defects of automotive structural parts. Therefore, large integrated die-casting components are currently mainly made of traditional Al—Si alloy without heat-treatment. However, the comprehensive mechanical properties of the traditional Al—Si alloys are poor, so it is urgent to develop a high-performance die-casting aluminum alloy without heat-treatment for automotive structural body parts. SUMMARY According to a first aspect of embodiments of the present disclosure, there is provided a die-casting aluminum alloy without heat-treatment, Based on a total weight of the die-casting aluminum alloy, the die-casting aluminum alloy includes: 6.0 to 8.0 wt % of Si; 0.3 to 1.2 wt % of Mg; 0.4 to 0.8 wt % of Cu; 0.1 to 0.3 wt % of Fe; 0.6 to 0.8 wt % of Mn; 0.05 to 0.20 wt % of Ti; 0.03 to 0.07 wt % of Sr; 0.03 to 0.07 wt % of Ce; 0.01 to 0.04 wt % of La; 0.01 to 0.1 wt % of Zr; less than or equal to 0.01 wt % of other impurity elements; and a balance of Al. According to a second aspect of embodiments of the present disclosure, there is provided a method for preparing the die-casting aluminum alloy without heat-treatment. The method includes: melting aluminum in a smelting furnace, adding thereto silicon, magnesium, a Cu raw material, a Fe raw material and an Mn raw material, and performing first smelting to obtain a first melt; transferring the first melt to a converter after the first melt is cooled down, adding a first material at a bottom of the first melt, and performing second smelting and first degassing, refining and deslagging to obtain a second melt; transferring the second melt to a holding furnace for component testing after the second melt is cooled down, and performing high-pressure die-casting on the second melt qualified after the component testing to obtain the die-casting aluminum alloy. The first material includes a Ti raw material, a Sr raw material, a Ce raw material, a La raw material, a Zr raw material and a Sn raw material, or the first material includes the Ti raw material, the Sr raw material, the Ce raw material, the La raw material and the Zr raw material. According to a third aspect of embodiments of the present disclosure, there is provided a structural part of an automobile body, which includes a die-casting aluminum alloy, and the die-casting aluminum alloy is the aforementioned die-casting aluminum alloy without heat-treatment, or the die-casting aluminum alloy without heat-treatment prepared by the aforementioned preparation method. It is to be understood that both the foregoing general description and the following detailed description are illustrative and explanatory only and are not restrictive of the disclosure, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are used to provide a further understanding of the present disclosure, constitute a part of this specification, and serve to explain the present disclosure together with the following descriptions, but do not constitute a limitation on the present disclosure. FIG. 1 is a process flow chart illustrating a preparation method of a die-casting aluminum alloy without heat-treatment according to embodiments of the present disclosure; FIG. 2 shows microstructure images of aluminum alloy castings prepared in Example 1 and Example 2 of the present disclosure; where images (a), (c) and (e) in FIG. 2 are microstructure images of the aluminum alloy casting prepared in Example 1, images (b), (d) and (f) in FIG. 2 are microstructure images of the aluminum alloy casting prepared in Example 2; the images (a) and (b) in FIG. 2 are optical micrographs, the images (c) and (d) in FIG. 2 are electron micrographs, and the images (e) and (f) in FIG. 2 are fracture morphology; FIG. 3 shows stress-strain curves of aluminum alloy castings prepared in Example 1 and Example 2 of the present