Effect of Tool Geometry and Process Parameters on the Mechanical and Microstructural Properties of AZ31B-SiC Composite

Abstract

This investigation explores the fabrication of AZ31B magnesium alloy surface composites, enhanced with silicon carbide particulate reinforcement via Friction Stir Processing, and characterizes their mechanical properties. The groove method facilitated the introduction of SiC reinforcement into the AZ31B matrix, a lightweight alloy recognized for its elevated strength-to-weight ratio. A systematic L9 orthogonal array design was implemented to modulate critical processing variables, including tool rotational speed, traverse speed, groove width, and tool pin geometry. Mechanical characterization encompassed tensile strength assessments and Vickers microhardness evaluations, alongside microstructural examination utilizing Optical Microscopy and Scanning Electron Microscopy. The configuration employing a square tool geometry, operated at 545 rpm and a 31.5 mm/min traverse speed, yielded the most refined grain morphology and a homogeneous distribution of SiC particles. This specific processing condition resulted in a peak tensile strength of 152.37 MPa and a hardness value of 100.54 HV. Conversely, elevated traverse speeds and expanded groove widths induced agglomeration of the reinforcement particles, thereby diminishing the mechanical performance of the resulting composites. The results conclusively demonstrate that optimizing FSP parameters is crucial for enhancing the microstructure and mechanical attributes of AZ31B-SiC surface composites, thereby broadening their applicability in diverse structural and lightweight engineering contexts.