Improved corrosion resistance and cytocompatibility of magnesium alloy by two-stage cooling in thermal treatment

A two-stage post-solution cooling procedure including 90 min of furnace cooling and subsequent water quenching is used to modify the morphology and distribution of the β-phase in magnesium-aluminum-zinc alloy. After this special process, the original coarse particle-like β-phase disappears and large-area fine lamellar (α + β) precipitates emerge. Dissolution of the coarse β-phase reduces the galvanic effects and produces the Al-rich α-phase matrix, whereas precipitation of the fine lamellar (α + β) micro-constituent forms a large number of almost continuous β-phase barrier. The microstructural change enhances the bio-corrosion resistance and cytocompatibility of magnesium alloy.