Empirical Modeling and Osprey-Based Optimization of AlSi10Mg Tensile Strength in Selective Laser Melting

Abstract

AlSi10Mg alloy, known for its better strength-to-weight ratio, corrosion resistance, thermal stability, and castability, led to its use for widespread engineering applications. Optimizing tensile strength ensures better structural and functional integrity of parts subjected to loading applications. The mechanical strength of parts is sensitive to selective laser melting (SLM) parameters. Improper setting of SLM parameters (laser power, focal plane, and scan speed) led to the introduction of defects (unmelted powders, porosity, keyholes, and weak bonding layer) that reduce the mechanical performance. The morphology of AlSi10Mg powder confirms the particle size of 30 ± 5 μm with spherical and single dispersed characteristics. The EDAX analysis confirms the aluminium, silicon, and magnesium compositions with 87.49%, 10.08%, and 2.43%, respectively. The experimental plan, as per central composite design (CCD), allows the investigator to analyze the SLM parameters on the tensile strength performance of printed parts. The scan speed contribution to enhancing the tensile strength performance is significant. All interaction factors were significant despite negligible contributions observed for the individual effects of laser power and focal plane. The impact of SLM parameters exhibits nonlinear behavior with tensile strength. The derived empirical relationships predict 10 test cases with a percent deviation ranging between −3.74% and +3.24%, resulting in a mean absolute percent error equal to 2.7%. Osprey Optimization Algorithm (OOA) determined condition maximizes the tensile strength to 392.4 ± 2.5 MPa, displaying a ductile fracture with minor dimples, keyhole cavities, and stream flow patterns.