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采用定量金相法，提取激光熔覆Ｃｏ基合金熔覆层不同部位的枝晶组织特征（枝晶二次臂间距ＤｅｎｄｒｉｔｅＳｅｃｏｎｄＡｒｍＳｐａｃｉｎｇ），结果表明：随着离熔覆层与基材结合界面距离的增加，熔覆层枝晶特征尺寸随之减小，即组织不均匀；同一高度下不同部位的特征尺寸变化不明显，即组织均匀。采用激光熔覆解析模型，计算了熔池局部凝固特性参数（温度梯度Ｇ、界面推移速度ＶＳ和冷却速率Ｔ．），结合凝固理论，解释了激光熔覆层组织形成原因。建立了熔覆层组织不均匀性评判标准，依据标准对熔覆层组织进行评判，并在此基础上提出消除组织不均匀性的方法。
Quantitative metallographic method was used to extract the dendritic structure (DendriteSecondArmSpacing) of different parts of laser cladding Co-based alloy cladding. The results show that with the increase of the distance from the interface between the cladding and the substrate, the melting The dendritic features decreased in size, that is, the microstructure was not uniform. The feature sizes of different parts did not change obviously at the same height, that is, the microstructure was uniform. The local solidification parameters (temperature gradient G, interface velocity VS and cooling rate T) of the molten pool were calculated by using the laser cladding analysis model. The reasons for the formation of the laser cladding layer were explained with the solidification theory. The evaluation criteria of the microstructure heterogeneity of the cladding layer were established, the microstructure of the cladding layer was evaluated according to the standard, and the method of eliminating the non-uniformity of the microstructure was proposed.