Optimization of Process Parameters for LPBF Forming GH3230 Superalloy Using RSM and MOPSO

GH3230 superalloy is widely used in aerospace hot-end components due to its excellent high-temperature strength and microstructural stability. To investigate the influence of process parameters on the forming quality of laser powder bed fusion (LPBF) GH3230 superalloy, a response surface model was established with laser power, scanning speed, scanning spacing, and interlayer rotation angle as the input variables, and roughness, densification, and hardness as the response values. The optimal process parameters were then obtained by multi-objective optimization of the response surface model combination utilizing the multi-objective particle swarm optimization (MOPSO) algorithm, and the predicted values were compared with the experimental values. Two sets of process parameters were systematically selected from the optimal Pareto front solution set for experimental validation. The relative errors of roughness are 0.38% and 2.76%, those for densification are only 0.08% and 0.09%, and those for hardness are only 0.50% and 0.56%, indicating that the developed model has high prediction accuracy. The results reveal that for LPBF-fabricated GH3230 superalloy, the optimal ranges of process parameters are as follows: laser power controlled within 210~235  W, scanning speed of 980~1158  mm/s, hatch spacing of 0.085~0.110  mm, and interlayer rotation angle of 45°~72°. This work provides a reliable basis for the high-quality LPBF forming of GH3230 superalloy.