(华南理工大学 机电工程系， 广州 510640)
摘 要: 研究了等离子喷涂Ni基WC型自熔合金涂层炉熔处理前后的组织形态。结果表明，经重熔处理后，涂层由富含孔隙、未熔颗粒的层状结构转变为致密的结晶组织结构，涂层与基材由机械咬合结合转变为冶金反应扩散结合，涂层的内聚强度和涂层/基材的结合强度都得以显著改善。涂层的相组成在重熔前后变化不大，均主要由γ-Ni固溶体相， Ni-B(Ni2B)， Cr-B(CrB)， Ni-Si(Ni5Si2)和WC硬质相等组成。由于等离子喷涂是一种快速凝固工艺，在喷涂态涂层中形成了部分非晶相，经重熔处理后，非晶相发生完全晶化。
关键字: 自熔合金涂层； 等离子喷涂； 重熔处理；组织结构
（Department of ElectroMechanical Engineering,
South China University of Technology,Guangzhou 510640, P.R.China）
Abstract:The WC+Ni base selffluxing alloy coating was fabricated by plasma sprayingand then remelted in furnace. The results show that, after being remelted, the coating's morphology changes from laminar structure containing some pores and unmelted particles to dense crystal structure, and the adhesion between coating and substrate transforms from mechanical combination to chemicometallurgical reaction combination, so the coating's cohesive strength and adhesive strength are improved remarkably. The remelted coating consists of γ-Ni, Ni-B(Ni2B), Cr-B(CrB), Ni-Si(Ni5Si2) and WC phases that are alike the one of plasma sprayed coating. A little amorphous phase lies in the plasma sprayed coating due to the rapid solidification process, and the amorphous crystallizes after remelting process.
Key words: self-fluxing alloy coating； plasma spraying； re-melting process； microstructure
