45钢表面电火花沉积多层YG8涂层的组织和耐磨性

Microstructure and wear property of multi-layer YG8 ESD coating on 45 steel

采用电火花沉积技术在45钢表面制备了YG8多层沉积涂层,研究了涂层的微观组织及耐磨性能。结果表明,通过优化的多层沉积工艺参数可以获得组织均匀致密且与基体呈冶金结合的沉积层,且比单层沉积层厚度更大、孔隙更少;沉积层主要由Fe3W3C,Co3W3C,W2C和Fe2C等相组成;沉积层中弥散分布有大量的超细碳化物颗粒;沉积层的最高硬度为1785.7 HV,平均硬度为1677.3 HV,其耐磨性能是45钢基体的2.1倍;沉积层的磨损机制主要是疲劳磨损,涂层中弥散分布的超细硬质相是沉积层硬度及耐磨性能提高的主要因素。

YG8 cemented carbide electrode was deposited on the surface of a 45 steel by electro-spark deposition （ESD） and formed a multi-layer WC coating. The microstructure and wear property of the coating were investigated. The results show that the coating with uniform and dense structure and metallurgically bonded to the 45 steel substrate can be obtained by muhi-layer deposition process using optimum parameters, which is thicker and has less defect than the single-layer coating. The coating consists of Fe3W~ C, Co3W3 C, W2C and Fe2C phases. Many uhra-fine carbide particles dispersedly distribute in the coating. The highest hardness of the coating is 1785.7 HV, while the average value is 1677.3 HV. The wear-resistance performance of the coating increases by 1. 1 times than that of the 45 steel substrate. The wear mechanism is mainly fatigue wear. Ultra-fine hard phases distributed in the coating dispersedly are the main factors leading to：the high hardness and wear resistance of the coating.