Performance optimization of friction stir welded AZ91D magnesium alloy using hybrid Entropy-VIKOR-Taguchi approach

Optimization of Friction Stir Welding (FSW) parameters is vital for enhancing the performance of AZ91D magnesium alloy welds that are commonly used in automotive and aerospace industries for their exceptional strength-to-weight ratio. The present study presents a novel hybrid Entropy-VIKOR-Taguchi approach for optimizing FSW process parameters to address challenges like low ductility and susceptibility to heat-induced defects. By optimizing rotational speed, weld speed, and tool tilt angle, the methodology achieved a 23% increase in ultimate tensile strength (93 MPa to 114 MPa), a 14% improvement in microhardness (90 Hv to 103 Hv), and a 45% enhancement in impact toughness (1.5 J to 2.7 J) compared to baseline conditions. The Taguchi method enabled efficient experimental design, entropy analysis quantified the significance of the parameters, and the VIKOR method identified optimal trade-offs between conflicting performance metrics. Scanning electron microscopy revealed refined grain structures and enhanced ductility in the weld zone. This integrated approach marks a meaningful step forward in designing lightweight and high-performance materials. It offers a clear and practical pathway to meet the increasing demand for durable and efficient components, particularly in industries like aerospace and automotive, where performance and reliability are non-negotiable.