ABSTRACT In the current study, WC-Co and Cr3C2-NiCr coatings deposited on 90MnCrV8 steel surface via an atmospheric plasma spray (APS) system were modified by the plasma transferred arc (PTA) welding method. Microstructural defects including micro-cracks, voids, pores, and non-uniform zones were determined in the APS deposited layers. The microstructural defects were terminated by the PTA melting process due to the dissolving pool at high temperature. Strong metallurgical bonding between the coating layer and substrate and columnar dendrites and inter-dendritic precipitates were observed during the PTA melting process. Following the PTA melting process, MC, M3C, and M7C3 hard phases were formed in the coating layers. The hardness and wear performance of the coating layers significantly increased due to the PTA surface modification. The main reason for the significant increases in wear performance corresponded to the newly formed hard carbide phases and elimination of microstructural defects via the PTA surface modification.

中文翻译：

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通过 PTA 表面熔化改善 APS 碳化物涂层的微观结构和摩擦学性能

摘要 在目前的研究中，通过等离子转移弧 (PTA) 焊接方法对通过大气等离子喷涂 (APS) 系统沉积在 90MnCrV8 钢表面上的 WC-Co 和 Cr3C2-NiCr 涂层进行了改性。在 APS 沉积层中确定了微结构缺陷，包括微裂纹、空隙、孔隙和不均匀区域。由于高温下的溶解池，通过 PTA 熔化过程终止了微观结构缺陷。在 PTA 熔化过程中观察到涂层和基体之间的强冶金结合以及柱状枝晶和枝晶间析出物。在 PTA 熔化过程之后，在涂层中形成了 MC、M3C 和 M7C3 硬质相。由于PTA表面改性，涂层的硬度和耐磨性能显着提高。