纯铜在表面机械研磨辅助下形成铝合金层的研究

Investigation on Al Alloy Layer Formation of Pure Copper Surface Subjected to Surface Mechanical Attrition Treatment

以纯铜为研究对象,通过添加铝粉进行不同时间表面机械研磨(SMAT)处理。用金相显微镜、X射线衍射分析仪和扫描电镜对处理后样品的组织结构及成分变化进行分析。采用X射线能量色散谱分析方法(EDS)分析Al元素在不同层的分布与含量。结果纯铜表面出现了明显的分层现象,同时铜铝发生互扩散,有铜铝合金形成。处理时间为120 min与处理时间为240 min合金层的厚度均约为35μm,并且合金层与基体变形层结合紧密。由于弹丸的冲击产生应力应变和大量储存能,使得原子的跳动频率增加,同时降低了扩散激活能,实现铜铝在较低温度下快速互扩散。

Taking Cu as the research object,and Cu/Al composite layers were fabricated respectively on the surface of pure copper matrix,surrounded by aluminum powder,and applied for surface mechanical attrition treatment（SMAT） for two different times.The composition distribution and microstructure of composite layers were characterized by means of OM,XRD and SEM.The distribution and content of aluminum element in different layers of the treated sample were examined by using EDS.The results show that Cu/Al alloyed layer appeares resulted from mutual diffusion between copper atoms and aluminum atoms,which is contributed to delamination.The thickness of 35滋m Cu/Al alloyed layers for both,combining with matrix deformation layer closely,are synthesized with different treatment time of 120 min and 240 min respectively.Due to the rising of stress,vacancy defects and storage energy,it is easy to conclude that the higher atomic jumping frequency and lower activation energy of diffusion are the reasons why mutual diffusion between copper and Al happened at low temperature.