Thermal stability, grain growth kinetics, tensile properties, and corrosion resistance of commercially pure (CP) magnesium can be tailored by zinc addition in conjunction with small additions of zirconium and rare earth (RE) elements, which need to be systematically investigated. Accordingly, the thermal stability, grain growth kinetics, tensile properties, and bio-corrosion resistance of hot rolled CP Mg, and ZK30 (Mg-3Zn-0.5Zr) and ZEK300 (Mg-3Zn-0.5RE-0.5Zr) alloys were compared in this work. As a thermomechanical processing route, hot rolling was used for grain refinement via dynamic recrystallization (DRX). The solute drag effect of Zn in the ZK30 alloy and the Zener pinning effect of CeZn 5 compound in the ZEK300 alloy were responsible for the improved thermal stability of the fine-grained microstructure and higher grain growth activation energy of these alloys compared to CP Mg. The tensile properties of hot rolled ZK30 and ZEK300 alloys were superior due to their fine grain sizes. Moreover, the potentiodynamic polarization test and electrochemical impedance spectrometry (EIS) analysis in the simulated body fluid (SBF) solution confirmed the higher corrosion resistance of the ZEK300 alloy for biomedical implant applications. The shear punch test (SPT) results revealed that the ZEK300 alloy can better retain its superior mechanical properties (e.g. the ultimate shear strength) during deformation/testing at elevated temperatures. Grain growth annealing led to a decrement in strength but an increment in the total elongation, and hence, the highest tensile toughness and improved strength-ductility balance were obtained for the ZEK300 alloy with an average grain size of similar to 8.5 mu m. Accordingly, this work proposed that RE addition at the micro-alloying level to a lean Mg-Zn alloy is quite effective in the enhancement of thermal stability, room/elevated-temperature mechanical properties, and bio-corrosion resistance.
