AZ31 Mg Alloy Processed by Equal Channel Angular Pressing for Bio-Medical Applications: The Role of Microstructure on SCC

Mg and Mg alloys are subjects of great interest in the scientific community due their unique properties for biodegradable implant applications (Young modulus and density close to that of human bone, good mechanical properties, biodegradability). The key challenge however is about their too high corrosion rate in human body environment. Some controversial statements are present in literature about the role of microstructure on corrosion resistance of Mg alloys in human body fluid; more investigations are indeed required. The aim of this work is to find a correlation between the microstructure and both corrosion and stress corrosion resistance of AZ31 undergone four ECAP passes. Results show that the best stress corrosion cracking resistance is provided by a partially recrystallized and textured microstructure made of a bimodal grain size distribution.