Microstructure, mechanical properties, and biocompatibility studies on severely surface-deformed Mg alloys

Abstract

The Developing surface engineering strategies to enhance magnesium alloys’ mechanical, tribological, and biological performance has received significant attention, particularly for biomedical and engineering applications. Surface Mechanical Attrition Treatment (SMAT), a severe surface plastic deformation technique, has emerged as a promising method for tailoring the surface properties of lightweight alloys through grain refinement, twin formation, and residual stress generation. In this work, two magnesium alloys were selected for investigation: (i) AZ91D alloy, which offers excellent mechanical and surface properties for general engineering applications but is limited in biomedical use due to its high aluminium content, and (ii) Mg5Zn0.2Ca alloy, a most biocompatible alloy free of aluminium, making it more suitable for biomedical applications. The present research systematically explores the role of SMAT process parameters, specifically ball velocity and surface coverage, on the microstructure evolution and mechanical, corrosion, and biocompatibility behaviour of the alloys.