Influence of fine‐grained structure produced by groove pressing on the properties of pure Mg and commercial ZE41 alloy

Abstract

AbstractBiodegradable metals are important for temporary implant applications. However, poor mechanical properties and higher degradation rate of Mg and its commercial alloys is a major disadvantage. In this study, the above properties were tailored using the groove pressing (GP) technique. Uniform fine‐grained (UFG) pure Mg and ZE41 alloy were obtained using GP technique. The impact of GP‐induced microstructural changes and surface characteristics on mechanical performance, degradation behavior, biomineralization, surface wettability, and cytocompatibility were investigated. The groove‐pressed pure Mg and ZE41 alloy had grain sizes of approximately 30 ± 7.8 and 25 ± 7.5 μm, respectively. The hardness of groove‐pressed pure Mg and ZE41 alloy increased by 40% and 26%, respectively, when compared to the annealed condition. Enhanced strength and elongation were observed with these samples. The potentiodynamic polarization test showed a higher Ecorr and lower Icorr values for groove‐pressed sample when compared to the annealed condition indicating decreased degradation rate. The weight loss data from immersion tests also show that the degradation rate decreases with time confirming the surface passivity of the sample. The degradation rate decreased by 37% and 44% in simulated body fluid for pure Mg and ZE41 alloy, respectively, after GP. The higher hydroxyapatite deposition on the groove‐pressed sample than the annealed sample, as observed from surface morphology studies after immersion in simulated body fluid, confirms the increased biomineralization tendency after GP. The higher wettability of the groove‐pressed sample leads to higher cell adhesion and cell viability when compared to the annealed sample indicating higher biocompatibility.