Preparation, microstructure and degradation behavior of Mg-2Zn-0.4Sc-0.2Zr alloy wire

Abstract

A biodegradable Mg-2Zn-0.4Sc-0.2Zr (ZK20-0.4Sc) alloy wire with a diameter of 0.5 mm was prepared by a combination of hot extrusion and cold-drawing. The average grain size of ZK20-0.4Sc alloy wire on the longitudinal section along the drawing direction is approximately 7.3 μm. The texture results show relatively strong 〈 $\text{11}\stackrel{-}{\text{2}}\text{0}$〉 and weak 〈 $\text{10}\stackrel{-}{\text{1}}\text{0}$〉 fiber texture components parallel to the drawing direction. The ZK20-0.4Sc alloy wire exhibits better mechanical properties with the tensile strength, yield strength and elongate of (329±2) MPa, (287±2) MPa and (14.2±0.5)%, respectively. The better mechanical properties are mainly attributed to the grain refinement strengthening, dislocation strengthening and precipitation strengthening. With the immersion time increasing to 14 d, the corrosion type transfers from filament corrosion and pitting corrosion to severe localized corrosion.