Uniform corrosion behavior of GZ51K alloy with long period stacking ordered structure for biomedical application

Mg–5Gd–1Zn–0.6Zr (wt.%, GZ51K) alloy was prepared by gravity casting in order to develop a novel, biodegradable magnesium alloy. The microstructure and corrosion behavior of the alloy exposed to simulated body fluid (SBF) were investigated under as-cast, solution and aging-treated conditions. The microstructure of the as-cast alloy consists of α-Mg, lamellar phase with long period stacking ordered (LPSO) structure, and eutectic phase. The LPSO phase disappears after solution treatment at 535 °C for 12 h, and the microstructure of the alloy after solution and aging treatment is composed of α-Mg and needle-like precipitates. The as-cast GZ51K alloy with LPSO structure exhibits slower corrosion rates and more uniform corrosion morphology as compared to the alloy without LPSO structure, and is thus desirable for use as a degradable biomaterial.