Method for improving high-temperature plasticity of nano-particle reinforced aluminum matrix composite

Abstract

The invention discloses a method for improving high-temperature plasticity of a nano-particle reinforced aluminum matrix composite. The method comprises the steps that (1) equipment is prepared; (2) the surface, to be machined, of the composite is subjected to oil removal and cleaning pretreatment; (3) the to-be-machined composite is placed in a cooling medium storage box; (4) high-purity argon issprayed to serve as shielding gas of a laser machining molten pool; (5) software is controlled through a laser controller to prefabricate a laser machining route; and (6) a laser generator and a laser machining platform are started to complete the set laser remelting machining route. According to the method, through high-speed stirring and rapid cooling solidification of the laser molten pool, analuminum matrix composite microstructure with fine grain structures and uniform nano-reinforced particle distribution is obtained, the microstructure effectively improves the high-temperature plasticity of the composite, and the machining method has the advantages of being simple in structure and wide in process applicability.

Description

technical field [0001] The invention relates to the technical field of modification of metal-based composite materials, in particular to a method for improving the high-temperature plasticity of nano-particle-reinforced aluminum-based composite materials, which is a modification treatment method for processing metal-based composite materials with high-energy beams. Background technique [0002] Aluminum Matrix Composite (AMC) has gradually become a key material for high-end manufacturing industries such as aerospace, and it is also a cross and link between new non-ferrous metal materials and the aerospace industry. Among them, particle reinforced aluminum matrix composite (PRAMC), as an important branch of AMC, has superior mechanical, electrical conductivity and heat resistance properties, and high volume fraction PRAMC theoretically has higher specific strength and thermal stability. Therefore, PRAMC has great development potential in lightweight applications such as aeros...

AI Technical Summary

Problems solved by technology

However, the in situ synthesis of PRAMC technology is still not perfect, especially when high volume fraction PRAMC is synthesized in situ, it is difficult to avoid the existence of many tissue defects:

Secondly, the casting process forms coarse dendrites, and the large axis ratio of dendrites is not conducive to superplastic deformation.

Since the superplasticity of aluminum alloy belongs to fine-grained superplasticity only, but the grain size and shape of the matrix are not satisfied, the matrix of as-cast PRAMC cannot obtain the fine-grain strengthening effect and fine-grained superplasticity;

[0005] (2) The dispersibility of the particles is poor and agglomeration occurs. The agglomeration of the particles will weaken its strengthening effect, and also have a greater negative impact on the plasticity and processability of the elongation index.

[0006] (3) Due to the above structural defects, the plastic deformation ability of the as-cast composite is poor, and the high volume / mass fraction PRAMC even has a phenomenon of greatly reduced elongation

[0007] The above-mentioned microstructural defects directly reduce the mechanical properties of composite materials, and because they do not have the plastic forming ability under high temperature conditions, the processing of in-situ synthesized PRAMC will be more restricted by equipment and process windows, which also restricts the dimensional accuracy of components, residual Improvement potential of product indicators such as stress

Images