高功率半导体激光器(HPDL)是新型先进装备,且体积小、电光转换效率高,在材料制备和加工方面具有良好的发展前景。使用3 kW高功率半导体激光设备,采用同步送粉的方式,在304不锈钢基体上制备絮状WC-Ni基超硬复合材料,获得了与基体冶金结合且无气孔和裂纹等缺陷的熔覆层。使用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)对激光熔覆层进行组织、成分及物相表征。研究结果表明,采用半导体激光进行熔覆可获得WC较高质量分数(60%)且稀释率很低的WC-Ni超硬复合材料。激光熔覆WC-Ni基超硬复合材料的组织主要是γ-Ni,WC,W2C,Ni3B,CrB2等物相组成。激光熔覆层的硬度不均匀,其平均值为HV 1100,远高于基体硬度HV 350,过渡区处硬度呈很窄的梯度分布。

High power diode laser (HPDL) is advanced portable equipment with the high value electrical to optical conversion efficiency. Diode lasers have seen wide applications in material fabrication and processing. Aggregate WC-Ni based superhard composites were fabricated on 304 stainless steel substrate. Wear-resistant coatings were fabricated by a 3 kW diode laser with direct injection powders into the molten pool. The coating had excellent bonding with the substrate and was free of pores and cracks. The morphology of laser cladding layer was observed by scanning electronics microscope (SEM),composition analysis was applied by energy dispersive spectroscopy (EDS),and the phase transformation was characterized by X-ray diffraction (XRD). The results showed that WC-Ni based superhard composites was fabricated by high power diode laser with high content tungsten carbide (60%) and low dilution. The main structure of diode laser cladding WC-Ni based alloy was γ-Ni,WC,W2C,Ni3B,CrB2 etc. The hardness of the laser clad layer is inhomogeneously distributed with the average value of HV 1100,higher than the substrate of HV 350. The hardness in the transition region is gradient distributed with steep reduction.