Effect of building orientation on the in vitro corrosion of biomedical Zn-Cu alloys prepared by selective laser melting

Zn-Cu alloys as biodegradable materials have been successfully fabricated by selective laser melting (SLM) method. XRD, EBSD, electrochemical and immersion tests have been conducted to investigate the effect of building direction on microstructure and in vitro degradation behaviors. Finer grains and more CuZn5 precipitates are found on vertically built Zn-Cu alloy, which results in a higher degradation rate than horizontally built one in both electrochemical and immersion tests. The corrosion mode includes general corrosion and pitting. The moderate corrosion rates of SLM Zn-Cu make them suitable for cardiovascular stents and the corrosion rate is controllable by fabricating methods.