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以Ni-Si-Nb-C混合粉末作为预置合金,采用横流CO2激光器进行激光熔覆处理,在高温合金表面制备原位合成NbC颗粒增强Ni3Si复合材料涂层。结果表明,采用合适的激光熔覆工艺参数,可获得NbC颗粒增强的以Ni3Si金属间化合物及γ-Ni固溶体为主要组成相的复合涂层。尺寸约在2~4μm的NbC颗粒弥散分布,与复合材料基体润湿良好,熔覆层致密,组织细小,与基材呈良好的冶金结合。晶体结构及动力学生长过程决定了NbC以不同的生长形态出现。
The Ni-Si-Nb-C mixed powder was used as the pre-alloy, and the laser cladding was carried out by cross-flow CO2 laser to prepare in-situ NbC particles reinforced Ni3Si composite coating on the superalloy surface. The results show that the composite coating with NiCb intermetallic compound and γ-Ni solid solution as the main component can be obtained by using suitable laser cladding parameters. The NbC particles with the size of about 2 ~ 4μm are dispersed and wetted well with the matrix of the composite material, the cladding layer is dense, the microstructure is fine, and the metallurgical bond with the substrate is good. The crystal structure and kinetics of growth determine that NbC appears in different growth patterns.