Microstructure, mechanical properties and fretting corrosion wear behavior of biomedical ZK60 Mg alloy treated by laser shock peening

Abstract

ZK60 magnesium alloy was treated with laser shock peening (LSP) technology at different laser energy densities. Fretting corrosion wear tests were conducted on the LSP-treated and untreated magnesium alloy samples in simulated body fluid condition. The microstructure, residual stress, surface hardness, tensile strength, and corrosion resistance were also tested to analyze their relationships with fretting corrosion wear behavior. Results showed that a maximum of 73.4% reduction of the fretting corrosion wear volume can be obtained by LSP treatment. The fine grain strengthening and the strain hardening caused by dislocation and twinning, and the compressive residual stress improve the surface hardness, tensile strength, and corrosion resistance at the same time, thus reducing the fretting corrosion wear.