Laser additive manufacturing method of in-situ synthesized nano Al2O3 reinforced aluminum-based composite material

Abstract

The invention discloses a laser additive manufacturing method of an in-situ synthesized nano Al2O3 reinforced aluminum-based composite material. The method comprises the following steps of (1) mixingZnO ceramic powders and AlSi10Mg aluminum alloy powders, and carrying out ball milling to obtain ZnO / AlSi10Mg composite powders; (2) carrying out additive manufacturing forming on the composite powders by adopting a selective laser melting process to form a solid sheet layer; (3) carrying out laser scanning on the solid sheet layer again to form a remelting sheet layer; (4) repeating the steps (2)and (3), and finally forming to obtain the in-situ synthesized nano Al2O3 reinforced aluminum-based composite material. A laser is used for exciting Al and ZnO to generate aluminothermic reactions between the Al and ZnO to generate Al2O3 ceramic particles in situ, the overall process design of the method is improved, selective laser melting and laser remelting scanning are matched, the prepared aluminum-based composite material is high in density and fine in microstructure, the in-situ synthesized Al2O3 particles are nanoscale in size and are uniformly distributed, and the phase interfaces ofthe Al2O3 particles are well combined with an aluminum matrix.

Description

technical field [0001] The invention belongs to the technical field of preparation of aluminum-based composite materials, and more specifically relates to an in-situ self-generated nano-Al 2 o 3 Laser additive manufacturing method for reinforced aluminum matrix composites. Background technique [0002] Aluminum matrix composite material is an advanced material compounded by a specific process with particles, fibers or whiskers as the reinforcing phase and aluminum or aluminum alloy as the matrix. Aluminum-based composites not only have the characteristics of good wear resistance, easy processing, and low density of the aluminum matrix, but also have the advantages of high hardness, low expansion coefficient, and high-temperature stability of the reinforcing phase. Due to its excellent comprehensive properties, aluminum matrix composites have become one of the best candidate materials in aerospace, rail transit and other fields. There are many traditional methods for prepa...

AI Technical Summary

Problems solved by technology

At present, the aluminum matrix composites formed by laser selective melting mostly use the direct external method to add the reinforcement phase, and seldom use the in-situ self-generation method. The reason is that the direct external method can flexibly introduce reinforcement phases of different sizes, shapes and contents into the aluminum In the matrix, the in-situ self-generation method still has problems such as difficult to control the reaction process, easy to form coarse and harmful phases, the heat released by the reaction makes the melt unstable, difficult to spread evenly, and the formed material has low density.

However, when the reinforcing phase is introduced directly, it will easily lead to uneven distribution of the reinforcing phase, agglomeration, and poor interface bonding with the matrix.

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