超音速等离子喷涂Cr2O3陶瓷涂层的微观组织及其耐磨性能

采用超音速等离子喷涂技术在纯铜基体上制备Cr2O3-Ni-5%A(l质量分数)陶瓷涂层。利用XRD、SEM、激光共聚焦显微镜(LSCM)、显微硬度仪对涂层进行表征与分析,通过Image-pro Plus图形软件计算涂层的孔隙率,并通过摩擦磨损试验评价涂层的耐磨性能。结果表明:除了喷涂过程中出现了少量铬的氧化外,起始粉末和涂层的物相没有发生变化;陶瓷涂层表面呈双态组织,其表面粗糙度(Ra)为4.763μm;涂层断口形貌为典型的片层状组织,在涂层的抛光截面上可见紧密的富铬带均匀分布;Cr2O3涂层的孔隙率为1.2%,显微硬度为1 640HV0.3;涂层在室温下的摩擦因数约为0.4,其磨损机制为磨粒磨损。

Microstructure and wear resistance of Cr2O3 based ceramic coatings deposited by supersonic atmosphere plasma spraying

Cr2O3 based ceramic coatings(Cr2O3-Ni-5%Al(mass fraction)) were deposited onto pure copper substrate by supersonic atmosphere plasma spray(SAPS).The coating was characterized by XRD,SEM,image software(Image-pro Plus) and laser scanning confocal microscope(LSCM).The results indicate that there is almost no change for phase compositions between the starting powder and the as-sprayed coating except for slight oxidation of chromium.The ceramic coating forms a duplex surface microstructure and possesses a surface roughness(Ra) of 4.763 μm.A typical porous lamellar structure is observed in the fracture surface of the as-sprayed coating.Chromium-rich regions are found to have a uniform distribution in the cross-section of sample.The coating possesses a porosity of 1.2 % and micro-hardness of 1 640HV0.3.The dry sliding wear at room temperature shows that Cr2O3 coating has a coefficient of friction of about 0.4 and the only relevant wear mechanism of abrasive wear.