High throughput corrosion screening of Mg-Zn combinatorial material libraries

Mg-Zn combinatorial material libraries covering 15–85 at.% Mg were deposited on glass substrates using magnetron sputtering at room temperature. To study the phases present in the Mg-Zn combinatorial libraries the as-deposited sample was annealed at 250 °C for an hour. The composition, phase content and thickness were characterized using energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and stylus profilometer respectively. The corrosion characteristics of the as-deposited and annealed combinatorial samples immersed in DPBS and PBS were evaluated using a high throughput novel optical screening technique. Corrosion maps of the combinatorial samples were generated from analysis of time lapsed images obtained from the novel optical screening technique. From the time lapsed images the corrosion rate of each composition in the combinatorial material libraries were evaluated. The results showed that compositions with Mg contents ≤40 at.% resulted in lower but similar corrosion rate for both as-deposited and annealed samples immersed in DPBS. The corrosion rate increases with increasing Mg content. Keywords: Combinatorial material libraries, Magnetron sputtering, Optical corrosion screening, Mg-Zn alloy