搅拌摩擦加工Al-Pb表面复合材料的微结构和织构

Microstructure and texture of Al-Pb surface composites fabricated by friction stir processing

摘要:

本文使用SEM、EBSD、纳米压痕和显微硬度等测试技术分析了搅拌摩擦加工Al-Pb表面复合材料的微观组织、织构和硬度分布。结果表明：使用FSP方法制备Al-Pb表面复合材料，Pb颗粒受到重力和搅拌作用，主要分布于盆状搅拌加工区的底部。塑性金属对流形成的洋葱环结构中，存在富Pb片层和形变铝基体片层。富Pb片层内的Pb颗粒，起到了良好的细化晶粒作用。变形铝基体片层分布有少量直径约100nm的新生Pb粒。受到细晶强化作用影响，富Pb颗粒区的硬度显著高于形变铝基体。加工区底部的SZ-AS区形成强Cube再结晶织构；SZ-RS区形成Cube织构和少量Brass织构；CSZ区的Cube织构较少，{111}织构增强；上部的AS区形成强Goss织构，RS区织构相对随机。

Abstract:

The friction stir processing (FSP) was employed to modify 1060 Al surface composites reinforced with Pb particles. The scanning electron microscopy, electron backscatter diffraction, nanoindentation and hardness tester were applied to investigate the microstructure, texture and hardness of Al-Pb surface composites. The results show that the Pb particles are mainly distributed at the bottom of processing area, which is effected by gravity and agitation. In the onion ring structure formed by plastic metal convection, there are Pb-rich zone and deformed Al matrix zone. The Pb particles in the Pb-rich zone play an importent role in grain refinement. A small amount of the new Pb particles (about 100 nm) are distributed in the deformed aluminum matrix. The hardness of Pb-rich zone are significantly higher than that of deformed aluminum matrix. Furthermore, crystallographic texture analysis by electron backscatter diffraction indicates that there are different types of texture in different zone in the processing area. At the bottom of the processing zone, there is a strong Cube texture on SZ-AS. SZ-RS has Cube texture and a small amount of (110)<233> deformation texture, and CSZ has weak Cube texture and {111} texture. At the top, there is a strong Goss texture on AS, but the texture on RS is relatively random.