Optimization of Selective Laser Melting Process Parameters Via Taguchi's Methods and Gray Relational Analysis for 3D Printing of 18Ni‐300 Maraging Steel

Abstract

Taguchi methods and gray relational analysis are used to determine optimal processing conditions for the selective laser melting (SLM) of 18Ni‐300 maraging steel. The following SLM process parameters are selected for optimization: laser power (P), scanning speed (v), and hatch spacing (h). Statistical analysis indicates that SLM parameter configuration no. 5 (275 W, 700 mm s−1, 0.08 mm) as most suitable for the simultaneous improvement of tensile strength, elongation (or ductility), hardness, and impact toughness. The order of influence of SLM parameters is identified as follows: . Samples with improved mechanical properties can be produced using configurations with higher linear energy density (). This is because the increased laser energy input facilitates complete melting of metal powder, as well as better interlayer bonding between melt pools. Higher can be achieved by either increasing P or decreasing v. Digital image correlation analysis indicates that tensile test samples with higher porosity exhibit lower ductility due to its inability to accommodate plastic strain accumulation for prolonged durations. Fractography analysis indicates that during tensile loading, cracks will nucleate around the pore perimeter and propagate via microvoid coalescence. Fracture will occur at regions with higher porosity due to it having multiple crack initiation sites.