高速激光熔覆Inconel 625/Y2O3复合涂层高温耐磨性能研究

Investigation of High Temperature Wear Resistance of Inconel 625/Y2O3 Composite Coating by High-Speed Laser Cladding

摘要:

添加碳化物和难熔金属元素，可以显著提高激光熔覆技术制备Inconel 625合金涂层的耐磨性，但添加氧化物对合金涂层的高温耐磨性的影响研究较少，其作用原理尚未揭示。为此，采用高速激光熔覆技术，在20G钢板基体上成功制备了Inconel 625涂层和Inconel 625/Y₂O₃复合涂层，并对他们的微观组织及高温耐磨性进行了系统地研究。结果表明：在凝固过程中Y₂O₃作为形核剂，其可使晶粒细化及晶粒取向分布更加随机；Inconel 625涂层和Inconel 625/Y₂O₃复合涂层均表现出在激光熔覆层/基体界面搭接处的硬度最高，与Inconel 625涂层相比，Inconel 625/Y₂O₃复合涂层搭接处的硬度更高约为275 HV_0.5；与基体和Inconel 625涂层相比，Inconel 625/Y₂O₃复合涂层具有更低的高温摩擦磨损系数，其高温摩擦系数仅为0.2；通过对比高温磨损后微观组织形貌后发现，Inconel 625/Y₂O₃复合涂层的耐磨性能最好。

Abstract:

Researchers have demonstrated that additions of carbides and refractory metal elements can significantly improve the wear resistance of Inconel 625 alloy coatings prepared by laser cladding. However， few research has been done on the wear resistance of Inconel 625 alloy coatings with the addition of oxides， and the mechanism is still unclear. Here， using high-speed laser cladding， Inconel 625 and Inconel 625/Y₂O₃ composite coatings have been successfully prepared on 20G steel substrates. The results suggest that Y₂O₃ has the capability of contributing to grain refinement， which facilitates the randomization of grain orientation during solidification. Inconel 625/Y₂O₃ composite coating has higher hardness than Inconel 625 coating， which is more than twice that of 20G matrix material， and the coating hardness is highest near the bonding interface between cladding layer and matrix （275 HV_0.5）. In addition， compared with the substrate and Inconel 625 coating， the Inconel 625/Y₂O₃ composite coating exhibits the lowest friction coefficient and the best high temperature wear resistance.