Post-corrosion mechanical performance of fine grained AZ31 Mg alloy sheets produced by groove pressing

Fine grained AZ31 magnesium alloy sheets were produced by groove pressing at 250 °C processing temperature targeted for biomedical implant applications. Microstructural studies revealed a grain refinement up to 12.5 ± 6.3 µm from 64 ± 14.5 µm. Higher hardness (95.1 ± 2.1 HV0.1) was measured for groove pressed AZ31 compared with AZ31 (58.7 ± 4.9 HV0.1). From the X-ray diffraction studies, basal dominated texture appeared in groove pressed samples. Corrosion performance assessed by conducting electrochemical studies using simulated body fluid (SBF) showed lower corrosion current density demonstrates increased corrosion resistance after groove pressing due to decreased grain size and texture. The post corrosion mechanical performance was assessed by conducting tensile tests after subjecting the samples to corrosion in SBF for 72 h. Grain refined AZ31 alloy exhibited improved strength with marginal decreased ductility before corrosion. Post corrosion experiments revealed better mechanical performance for the grain refined alloy as reflected in higher strength and % of elongation than the base alloy. The findings demonstrate the potential of grain refinement by groove pressing on enhancing resistance towards corrosion initiated mechanical failure of AZ31 in the presence of corrosion defects.