电火花沉积Fe基涂层的组织及耐磨性能

Microstructure and Wear Properties of Fe-based Coating Prepared by Electrospark Deposition

通过电火花沉积技术在P20模具钢表面制备了Fe基涂层,利用SEM,XRD及摩擦磨损试验机等分析了涂层的组织结构、显微硬度及耐磨性能。结果表明:电火花沉积Fe基涂层组织均匀、致密;涂层中靠近界面处的组织为柱状枝晶,而涂层中上部组织为超细晶粒。涂层的平均硬度为637.1HV0.1,相比基体提高了1倍;涂层耐磨性优于基体,涂层中弥散分布的Cr7C3,CrB及Fe3C等硬质是Fe基涂层硬度及耐磨性提高的主要原因。涂层的磨损机理主要为磨粒磨损的微切削和疲劳磨损。

The Fe-based alloy coating was produced on the surface of P20 steel plate by electro-spark deposition （ESD） technique, and the mierostructure and wear properties of the coating were investigated by SEM, XRD and friction and wear test machine. The results show that the coating has homogenous and dense structure with fine dendritic structure in the bottom of the coating and ultra-fine grains in the middle and upper coating. The average hardness of the coating is 637.1 HV0.1. The wear resistance of the ESD coating is much higher than the substrate. Dispersion strengthening result from hard phases such as Cr7C3,CrB,Fe3C is the main factor leading to high hardness as well as wear resistance of the coating. The wear mechanism are mainly abrasive wear and fatigue wear.