Optimization of L-PBF Process Parameters for Defect Reduction and Mechanical Strength of Ni-Cr-Mo-Nb Superalloy Using...

In the context of Additive Manufacturing (AM), particularly the Laser Powder Bed Fusion (L-PBF) technique, optimizing process parameters is essential for achieving dense, defect-free materials. This study investigates the optimization of L-PBF process parameters for a Ni-Cr-Mo-Nb-based superalloy using an integrated three-stage methodology. Stage A applies Grey Relational Analysis to identify the most favourable parameter sets. Stage B uses Response Surface Methodology to develop regression models that correlate process parameters with material characteristics, introducing the specific energy of layer fusion as a key factor. Stage C employs the Gradient Ascent Method to determine the global optimum using a desirability function. The proposed approach reduces the number of required experiments while ensuring optimal mechanical properties: yield strength of 774.73 ± 4.94 MPa, tensile strength of 1022.83 ± 5.19 MPa, and elongation at break of 23.1 ± 0.70%, with minimal LoF area (0.003 mm²) and gas pore diameter (0.02 mm). The results demonstrate that integrating Grey Relational Analysis, Response Surface Methodology, and the Gradient Ascent Method effectively identifies the printability window, accelerating material characterization.