Method for preparing Al-Zn-Mg-Cu series aluminum alloy part by adopting powder metallurgy method

Abstract

The invention relates to a method for preparing Al-Zn-Mg-Cu series aluminum alloy parts through a powder metallurgy method, and belongs to the technical field of aluminum alloy parts prepared through the powder metallurgy method. The preparation method comprises the following steps: uniformly mixing pure Al powder and four kinds of alloy element powder or binary alloy powder of Mg, Zn, Cu and Sn according to a certain proportion, and carrying out pressing forming, sintering and heat treatment to obtain the aluminum alloy part. The Al-Zn-Mg-Cu series aluminum alloy system suitable for the pressing-sintering process is designed, the process for preparing the Al-Zn-Mg-Cu series aluminum alloy through the powder metallurgy method is optimized by controlling grain composition, pressing pressure, sintering process parameters and the like, the production efficiency is improved, and the production cost is reduced. The compactness of the Al-Zn-Mg-Cu series aluminum alloy material prepared through the method is higher than 98%, and the tensile strength of the Al-Zn-Mg-Cu series aluminum alloy material is larger than 470

Description

technical field [0001] The invention relates to a method for preparing Al-Zn-Mg-Cu aluminum alloy parts by powder metallurgy, and belongs to the technical field of metal parts prepared by powder metallurgy. Background technique [0002] In recent years, with the gradual miniaturization and lightweight development of automobiles, 3C products, 5G communications, wearable devices, and industrial robots, the demand for lightweight, high-strength, small and complex-shaped structural parts is increasing. The use of high-strength aluminum Replacing traditional iron-based materials with alloys is an important way to achieve lightweight. The preparation of small and complex aluminum alloy parts by means of machining, casting and 3D printing has problems such as high cost and unfavorable mass production. The powder metallurgy process has unique advantages in the preparation of small complex shape parts. [0003] Regarding the research on powder metallurgy aluminum alloys, the curren...

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Problems solved by technology

The invention is characterized by the following two aspects: First, the composition range of the aluminum alloy disclosed in the invention is too wide, Cu, Mg, Si, Zn and other elements far exceed their solid solubility in aluminum, so the alloy material after sintering The interior must contain a large amount of Al with a large size 2 Cu, MgZn 2 And elemental silicon and other brittle phases, these phases cannot be eliminated by solid solution treatment, it is difficult to control the size and distribution of these coarse second phases, thus affecting the mechanical properties of the material, but can increase the wear resistance of the material; secondly, the The composition of the invention contains 0% to 10% of SiC and Al 2 o 3 , graphite and other reinforcement phases, the existence of these reinforcement phases can improve the wear resistance of the material, but due to the wide variety of reinforcement phases, the problem of interfacial bonding of the reinforcement phases cannot be solved, so the mechanical properties must not be high

[0005] In summary, the mechanical properties of powder metallurgy aluminum alloys are generally not high at present, and there are still the following main difficulties in the preparation of Al-Zn-Mg-Cu high-strength aluminum alloys by powder metallurgy: ① lack of Al-Zn-Mg that meets the sintering characteristics -Cu-based aluminum alloy composition, difficult to sinter and densify

The existing powder metallurgy Al-Zn-Mg-Cu alloys are all based on the standard composition of wrought aluminum alloys, and there is no Al-Zn-Mg-Cu alloy composition suitable for the pressing-sintering process; Dense oxide film, which will hinder the diffusion and densification process of atoms between powders during sintering, so it cannot be prepared completely according to the traditional 7-series aluminum alloy composition, and it is necessary to design an Al-Zn-Mg-Cu alloy that can be sintered and densified Element

②Different from traditional casting and forging aluminum alloys prepared by smelting process, powder metallurgy aluminum alloys rely on the instantaneous liquid phase formed during sintering, so it is necessary to strictly control the content of alloying elements in aluminum alloys; ③About powder metallurgy Al-Zn-Mg There are few studies on the process parameters of -Cu alloys, such as the influence of particle gradation, pressing pressure and sintering process on the densification of materials, etc.

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