喷涂与激光重熔技术制备镍基纳米钴包碳化物复合涂层的研究

采用横流2．0kW CO2激光器，在45钢表面制备了表面较平整、较细密、基本消除了裂纹与孔隙并与基体呈冶金结合的镍基纳米WC／Co复合涂层。通过SEM，EDAX，XRD，AFM及Nano Indenter XP分析了熔覆层的显微组织、成分、物相及结合强度。结果表明，涂层的显微组织为涂层中镶嵌着大量与Ni基合金结合良好的WC／C。颗粒，其中在原子力显微镜下可见相当数量的粒度≤100μm的纳米颗粒。涂层的结合强度比传统热喷涂涂层提高了2．1倍。涂层中纳米WC／Co的纳米效应在激光熔覆中起着重要作用。

Study on Nickel-based Nano-WC/Co Composite Coating Prepared by Spraying and Laser Cladding

A nickel-based nano-WC/Co composite coating on 45 steel was gained with continuous wave CO2 laser of 2.0 kW, the surface of which is smooth and fine without crack or pore and metallurgically bonds with matrix. Microstructure, composition, phase and bonding strength of the coating have been tested by means of SEM ,EDAX, XRD, AFM and Nano Indenter XP. The results indicate that there are a large amount of WC/Co particles well- bonding with the Ni-based alloy in the microstructure of coating ,including a considerable amount of nano-particles with granularity of 100 nm or less visible under nanoscope atomic microscope. The bonding strength of coating is 2.1 times larger than that of conventional hot-sprayed coating . The nano-effect of WC/Co in the coating plays an important role during the laser cladding.