ABSTRACT

In this study, the (FeMnCrNiCo + 20%TiC) laser cladding layer was re-treated through multiple-pass in-situ laser remelting. Optical microscopy, scanning electron microscopy, and X-ray diffraction were used to analyse the evolution of microstructures and phases before and after the in-situ laser remelting processes. The micro-hardness and wear resistance of the composite coatings were systematically investigated using micro-hardness and abrasion. Results show that in-situ laser remelting decreased the dilution rate. The thermal effect of laser melting and the Maragni action in the liquid coating metal enabled the large-sized and loosened ceramic particles to remelt into the cladding layers. As a result, the ceramic particles in the cladding layers after in-situ laser remelting were modified considerably in terms of their spherification rate, dimension uniformity, and particle distribution. The weak spots caused by stress on the surfaces of the cladding layers were reduced, and accordingly the wear resistances improved.

摘要

在这项研究中，（FeMnCrNiCo + 20％TiC）激光熔覆层通过多道原位激光重熔进行了后处理。光学显微镜，扫描电子显微镜和X射线衍射用于分析原位激光重熔过程前后的微观结构和相的演变。利用显微硬度和耐磨性系统研究了复合涂层的显微硬度和耐磨性。结果表明，原位激光重熔降低了稀释率。激光熔化的热效应和液态金属涂层中的Maragni动作使大尺寸且疏松的陶瓷颗粒重新形成覆层。结果，原位激光重熔后，覆层中的陶瓷颗粒的球化率发生了显着变化，尺寸均匀性和颗粒分布。减少了由应力在包层表面上引起的弱点，因此提高了耐磨性。