Heat-treatment process control for microstructure and properties of laser cladding WC@Ni/Ni60 coating
MEI Mingliang1，HUANG Xu2，LIU Chang2.
（1. College of Intelligent Manufacturing, Fujian Polytechnic of Information Technology, Fuzhou 350003, China;
2.School of Mechanical and Automotive Engineering, Fujian University of Technology, Fuzhou 350118, China）
Abstract：The heat treatment process is important to improve the forming quality of laser cladding coatings. In
this paper WC@Ni / Ni60A and rare earth mixed powder were used to investigate the influence of different heat
treatment processes on the microhardness, microstructure, phase composition, and residual stress of the cladding
layer and to explore the optimal annealing temperature. The results show that increasing heat treatment temperature
decreases the coating microhardness. Higher microhardness of the coating can be obtained at 700 ℃. Samples with
1% La
2O3 and with 0.5% Y2O3 have a hardness of 64.9HRC and 65.3HRC, respectively. With the increase of heat
treatment temperature, the wear volume becomes larger. At an annealing temperature of 700 ℃, the friction coeffi‐
cient of the sample is lower than that of the untreated one. The increase in heat treatment temperature helps to re‐
duce the residual stress. Considering the performance indexes, the optimal heat treatment scheme includes the fol‐
lowing parameters: the heating temperature is 700 ℃, the heating speed is 10 ℃/min, the insulation time is 60 min,
and cooling mode is furnace cooling. The results provide a theoretical basis for improving coating quality through
heat treatment.
2023, Vol. 33 
