Process Parameter Optimization of a Laser Clad Fe-Based Alloy Using Response Surface Methodology (RSM)
J-Y. Lin, B. Han, X-R. Han, H. Wang and W-H. Cui
Given the severe waste of cold work moulds in the small batch production stage, a low cost 45 steel surface laser cladding Fe901 coating was proposed to replace cold work mould steel in this stage. Combining with the performance requirements of moulds, the laser cladding process parameters were optimized with the coating surface hardness as the goal. The optimized process parameters were laser power, powder feeding rate and scanning speed. 20 runs of cladding tests were carried out based on the central composite design method. Using Design-Expert software, the hardness-process parameter objective function model was obtained, and the reliability of the model was verified. The cladding process parameters were optimized based on the response surface method. It was found that the optimal ranges of laser power were 1600 to 2100 W, scanning speed were 9.5 to 13.0 mm/s and powder feeding rate were 24.0 to 34.0 g/min. This conclusion showed that the coating could reach the hardness index of cold work die steel.
Keywords: High power diode laser (HPDL), 45 steel, mould steel, Fe901, coating, laser cladding, hardness, process parameter optimization, central composite design (CCD), response surface methodology (RSM)