Morphology Control and Process Optimization for the Laser Cladding of Ni60 Alloy onto H13 Steel
J-H. LI, S-L. Xue, F-P. Yao, X-J. An and J-B. Jin
Using a fibre laser, the effect law of laser cladding process parameters on the morphology quality and dilution rate of Ni60 alloy powder clad onto H13 steel was examined. Laser power, scanning speed, powder feeding voltage, clad layer width, clad layer height, meltpool depth, the ratio of width to height and the dilution rate were established by response surface methodology (RSM) though a central composite design (CCD). The correctness of the mathematical model was verified by analysis of variance (ANOVA) and test index. The results show that the width of the laser clad layer is negatively correlated with the scanning speed, and the influence of laser power and powder feeding voltage is not significant. The height of the laser clad layer is positively correlated with the powder feeding voltage and negatively correlated with the scanning speed, and the laser power has no significant effect on it. The depth of the meltpool is positively correlated with laser power and negatively correlated with scanning speed and powder feeding voltage. The aspect ratio and dilution rate are positively correlated with the laser power and scanning speed, and negatively correlated with the powder feeding voltage, and the influence of the powder feeding voltage on them is the most significant. The process parameters were optimized with the fixed range of aspect ratio and the minimum dilution rate as the objectives. Through experiments, the average errors of predicted and actual value of aspect ratio and dilution rate are 8.1 and 11.1%, respectively. The research results provide a theoretical basis for the morphology control of single laser clad coating and the optimization of process parameters.
Keywords: Fibre laser, H13 steel, Ni60 alloy, powder, laser cladding, response surface methodology (RSM), central composite design (CCD), data optimization, morphology control