Crafting Multifunctional Materials with Tailored Mechanical and Magnetic Properties by Solid-State Non-equilibrium Processing

Abstract

Aluminum matrix composites hold promise for creating lightweight structural components with multifunctional properties. Nonetheless, achieving desired magnetic or electrical characteristics without compromising their fundamental mechanical properties presents a significant challenge. Here, we explore mechanical stir-based extrusion as a solid-state metalworking technique to develop fine-grained microstructures and highly refined metallic composites. Our study focuses on creating a SmCo₅-reinforced aluminum matrix composite using solid stir extrusion (SSE) and assessing its microstructure, mechanical, and magnetic properties through a comprehensive suite of characterization tools, including x-ray diffraction, electron microscopy, and magnetometry. Our findings reveal that incorporating a small amount (3.76 wt.%) of SmCo₅ phase in a non-heat-treatable, non-magnetic aluminum alloy via SSE yields a composite that exhibits good hard magnetic characteristics with a large coercivity (H_ci = 13.5 kOe) and improved mechanical properties. This study underscores non-equilibrium processing via solid-state high-speed stirring as a compelling method for crafting multifunctional materials with tailored mechanical and magnetic properties.