激光熔覆工艺参数对Ni60硬度和显微组织的影响

Effects of Laser Cladding Process Parameters on Hardness and Microstructure of Ni60

采用正交实验法研究了激光熔覆过程中相对工艺参数对Ni60合金粉末组织和显微硬度的影响。对不同参数下试样的显微硬度和显微组织进行分析。结果表明:不同工艺参数下熔覆层的显微硬度差异不大,主要集中在680~720 HV,而熔覆层的高度波动较大。熔覆层晶体结构尺寸随过冷度的增加先减小后增大;随着稀释率的降低,晶体尺寸逐渐减小,熔覆层的组织大致呈枝晶、等长线、背向和面状或者胞状晶体与柱状晶体转变或其中几种转变之间的关系。

The effects of relative process parameters on the microstructure and microhardness of Ni60 alloy powder during laser cladding were studied by orthogonal test method.The microhardness and microstructure of different parameters were analyzed.The results show that the microhardness of the cladding layer under different process parameters is basically the same,mainly concentrates in 680-720 HV,and the height of the cladding layer fluctuates greatly.The crystal structure size of the cladding layer decreases first and then increases with the increase of the degree of subcooling.As the dilution rate decreases,the crystal size decreases gradually.The microstructure of the cladding layer is roughly dendritic,isometric,back or the relationship between a planar or cellular crystal and a columnar crystal transition or several of these transitions.