Improving the Corrosion and Wear Behaviour of ECAP-Processed Biodegradable Mg-Zn-Ca Alloy for Bone Repair Applications

In this work, biodegradable Mg–3Zn–0.4Ca (ZX30) alloy was processed using equal channel angular pressingEqual channel angular pressing for up to 4-passes of route Bc. Microstructural evolutionMicrostructural evolution and crystallographic textureCrystallographic texture of the billetsBillet were studied using the scanning electron microscope-based electron back scatter diffraction technique. The corrosion behaviourCorrosion behaviour of the alloy was investigated using potentiodynamic polarization and electrochemical impedanceImpedance spectroscopy, set in a body simulated fluid. Wear tests were conducted for ZX30 billetsBillet as functions of load, velocity, and distance. The microstructureMicrostructure of the 4-passes samples was dominated by fine equiaxed grains, which indicates that the deformation processProcess was homogeneous and had caused continuous dynamic recrystallizationDynamic recrystallization. The average grain size of the 4-pass ZX30 alloyZX30 alloy was reduced by 91.6% compared to its as-annealed counterpart. A 93.4% corrosion rateCorrosion rates reduction, and a 254% corrosionCorrosion resistance improvement was achieved in the 4-passes condition. Furthermore, ECAP processing yielded significant improvements in wear behavior, compared to as-annealed counterpart.