In terms of aluminum alloy matrix composites, the effect of reinforcement on precipitation is worth investigating. In this work, the silicon carbide nanoparticles-reinforced 7075Al (SiC np /7075Al) composite was fabricated through a series of powder metallurgy procedures, shift-speed ball milling, hot pressing, and hot extrusion, and the precipitation behavior of SiC np /7075Al composite was compared with that of 7075Al alloy after T6 treatment. The results show that only a small addition (1 vol%) of SiC np modifies the morphology and dispersion of precipitates. The uniformly dispersed small precipitates (η′ phase) and increased dislocation density have a positive influence on the mechanical properties of composites. Based on the fracture surface and element composition, a fracture mode dominated by precipitated phase-induced crack initiation was proposed. This study suggests a promising approach to design the alloy matrix composites through controlling the behavior of precipitated phases with nano-reinforcement.

中文翻译：

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SiC纳米颗粒对7075Al合金析出行为及力学性能的影响

就铝合金基复合材料而言，增强对析出的影响值得研究。在这项工作中，碳化硅纳米粒子增强 7075Al (SiC np /7075Al) 复合材料通过一系列粉末冶金程序、变速球磨、热压和热挤压制备，并研究了 SiC np /7075Al 的析出行为T6 处理后的复合材料与 7075Al 合金的比较。结果表明，仅少量 (1 vol%) 的 SiC np 会改变沉淀物的形态和分散。均匀分散的小析出物（η'相）和增加的位错密度对复合材料的力学性能有积极影响。根据断裂面和元素组成，提出了一种以析出相诱导裂纹萌生为主的断裂模式。该研究提出了一种通过控制具有纳米增强作用的沉淀相的行为来设计合金基复合材料的有前途的方法。