目的 对热喷涂涂层进行表面改性。 方法 利用搅拌摩擦加工技术多道次加工制备复合层,分析受影响区涂层和基体的显微组织、元素扩散、显微硬度变化规律。 结果 形成了均匀致密且细晶化、涂层与界面消失、靠近涂层部分基体发生动态再结晶的复合层。 从涂层到基体形成了有层次的 260 μm 厚度渐变影响区,依次为:BZ,RLS,FRZ,ECZ。 温度场和塑性变形的耦合作用为涂层和基体元素互扩散提供了有利通道,发生了快速元素互扩散。 细晶强化和元素扩散共同作用使显微硬度显著提高,机械性能得到改善。 结论 搅拌摩擦加工技术能有效改善热喷涂涂层的组织和性能。

Objective To improve the thermal spraying coating layer. Methods Composite layer was prepared by using multipass friction stir processing technology. The transformation regulation of microscopic structure, element diffusion and microhardness were analyzed both on the affected area coating layer and substrate. Results A composite layer of uniform density and fine crystallization, interface of coating layer and substrate disappeared, dynamic recrystallization occurred was formed. A 260 μm hierarchical gradient affected zone was formed from the coating layer to the substrate: BZ, RLS, FRZ, ECZ. The coupling effect of temperature and plastic deformation provided favorable channel to fast element interdiffusion. Combination of fine-grain and elements diffusion obviously improved the microhardness and mechanical performance. Conclusion Friction stir processing technology can effectively improve the microscopic structure and properties of thermal spray coating layer.