The Ni-based WC composite（Ni-WC） coating on mould steel 2738 was prepared by CO2 laser cladding. The substrate 2738 steel and the Ni-based WCCC were tested under dry sliding friction conditions to investigate their friction and wear behavior. The wear volume of specimen was measured using a 3-D surface profilometer, and the worn surface topography was observed by the scanning electronic microscopy. The results show that the microhardness of the Ni-WC coating was enhanced significantly, its surface hardness exceeded 1200 HV, ensuring its wear resistance. The average friction factor was about 0.25, it decreased by about 44% in comparison with that of the substrate 2738 steel of 0.43. WC hard phase enhanced the hearing capacity of the friction surface, reduced the wear rate by 96.7%. The abrasive wear was the main wear mechanism for the Ni-WC coating.%在2738模具钢表面通过CO2激光熔覆制备Ni基WC复合涂层。分别对2738钢基体和Ni-WC激光熔覆层进行干摩擦试验。用三维表面形貌仪测量磨损体积，用扫描电镜观察磨痕的表面形貌。试验结果表明，Ni-WC复合涂层试样的硬度显著提高，表面硬度超过1200HV，保证了Ni-WC熔覆层的耐磨性。熔覆层的平均摩擦因数约为0．24，与2738钢基体的摩擦因数0．43相比，降低了约44％。熔覆试样的比磨损率比基体试样的比磨损率下降了96．7％，WC硬质相提高了摩擦副表面的承载能力。磨粒磨损为Ni-WC复合涂层的主要磨损机理。
展开▼
