Preparation, mechanical and degradation properties of Mg-Y-based microwire.

Abstract

Mg-Y-based microwire which offers high strength in combination of low degradation rate has been prepared for the first time by a modified melt extraction technique. A circular Mg-Y-based microwire is achieved with an extraction rate of 40m/s, which is composed of Mg matrix and an amorphous phase, and exhibits higher basal texture than that of as-cast sample. The outstanding tensile strength accompanying with an acceptable elongation is obtained with an extraction rate of 40m/s. The improved strength is mainly attributed to high solid solution strengthening, fine grain and the presence of an amorphous phase. In addition, the reduction of secondary phase and homogenous microstructure after melt extraction eliminate both pitting corrosion and micro-galvanic corrosion. A low degradation rate of 0.366mm/y is attained in a simulated body fluid, which is less than 1/10 of that of as-cast sample. These excellent mechanical properties and low degradation rate provide some prerequisites to develop bio-Mg implants. It reveals that this modified extraction technique is one of effective approaches to prepare microwire, which can be directly used for Mg-based stent self-assembly.