Optimization of mechanical properties and corrosion resistance of Zn-0.4Mn-0.8Li alloy using the hot rolling process

Abstract

Zinc-based degradable metals are considered one of the most promising biodegradable materials due to their moderate corrosion rate, excellent mechanical properties, and good biocompatibility. In this work, biodegradable Zn-0.4Mn-0.8Li alloy was fabricated and rolled in multiple passes at different temperatures. As the hot rolling temperature increases, the grain size of Zn-0.4Mn-0.8Li alloy was found to increase correspondingly. Further, a multi-scale structure with the coexistence of coarse grains and fine grains was obtained. The results demonstrated that the mechanical strength and corrosion resistance were improved by increasing the rolled temperature. It was observed that Zn-0.4Mn-0.8Li alloy with a total reduction of 90% after hot rolling at 325 °C exhibited excellent mechanical and corrosion properties. The cooperation of multi-scale microstructure and twinning was found to improve the strength and guarantee the ductility of Zn-0.4Mn-0.8Li alloy significantly so that the 325 °C hot-rolled Zn-0.4Mn-0.8Li alloy has optimal comprehensive properties. Further, yield strength, ultimate tensile strength, and elongation were found to be 449.7 ± 5.3 MPa, 505.1 ± 6.5 MPa, and 40.5% ± 7.5%, respectively. Meanwhile, Zn-0.4Mn-0.8Li alloy via 325 °C hot-rolled processes also exhibited excellent corrosion resistance. The corrosion current density and corrosion potential were found to be 8.8 × 10–5 mA cm–2 and −0.929 V, respectively. The preliminary study indicates that Zn-0.4Mn-0.8Li alloy is a promising candidate material for medical device applications.