等离子喷涂Fe基合金涂层组织及接触疲劳损伤性能的研究

摘要

Fe-based alloy coating was prepared on 1045 steel by the supersonic plasma spraying device. The microstructure of the coating was characterized using scanning electron microscopy (SEM) , X-ray diffraction (XRD) and transmission electron microscopy (TEM). Microhardness of coating cross-section was measured using microhardness tester. Process of contact fatigue damage was monitored using acoustic emission technology on a ball-on-disk tester. The results show that the microstructure of the coating consists of o(Fe,Cr) phase and reticular Cr7C3. Nanocrystalline a(Fe, Cr) phases were homogeneously distributed around the cracks. Damage degree of contact fatigue could be reflected by RMS of acoustic emission parameter. Delamination is the final failure mode of the coating when the contact stress is 1. 8489GPa and rotational speed is 2000r/min.%使用超音速等离子喷涂设备在45钢基体上制备了铁基合金涂层,采用扫描电镜、透射电镜、X射线衍射仪等设备对涂层的组织结构进行了表征,借助显微硬度仪测定了涂层截面的硬度分布,以球盘式接触疲劳试验机为平台,利用声发射技术实时监测涂层的接触疲劳损伤过程.结果表明,涂层组织主要是由α(Fe,Cr)相和网状的Cr7C3组成,纳米级α(Fe,Cr)相分布于裂纹周围.声发射特征参数RMS可以反映涂层的接触疲劳损伤程度,在转速为2500r/min和应力水平为1.8489GPa实验条件下,分层是涂层失效的最终形式.