Effect of multi‐axial hot forging process on mechanical, and corrosion resistance behavior of Mg‐3Zn alloy for temporary orthopedic implants

Abstract

AbstractMagnesium (Mg) is a load‐bearing biocompatible material which has the ability to reduce stress shielding effect and facilitate osteocompatibility and biodegradation in the presence of body fluids. However, Mg is highly susceptible to corrosion in the physiological environment, hence leading to poor mechanical integrity. In this study, the multi‐axial hot forging (MAHF) process is performed on Mg‐3Zn alloys to study its grain refinement and possible improvement in mechanical, corrosion, and bioactivity behavior. The average grain size of the sample becomes significantly refined after the third cycle of MAHF. The yield and ultimate compressive strength of Mg‐3Zn alloys are found to increase by 70% and 41%, respectively, after the third cycle of MAHF, which is potentially due to the grain size refinement. Accelerated corrosion studies show improvements in the corrosion resistance with the refined grain structure. Additionally, in‐vitro immersion studies in the simulated body fluid for 14 days showed a reduction in the degradation rate after third cycle of MAHF, due to the increased grain boundary area, which offered more nucleation sites for apatite precipitation. This study underscores and lays the foundation for a new branch of severely deformed fine‐grained Mg‐3Zn alloy for temporary orthopedic implants.