Effects of ECAP extrusion on the mechanical and biodegradable properties of an extruded Mg-1.5Zn-0.5Y-0.5Zr alloy

Severe plastic deformation such as equal channel angular pressing (ECAP) could change the mechanical and corrosion resistance of Mg alloys. The effects of ECAP extrusion on the mechanical and biodegradable properties of an extruded Mg-1.5Zn-0.5Y-0.5Zr alloy were studied in this work. After two passes and four passes ECAP extrusion, the microstructure, mechanical properties and degradation behaviours were investigated. It showed that with increase of the extrusion pass, the average grain size of the alloy decreased greatly. After four passes extrusion, the grain size was about 1.37 ± 0.22 μm. The ECAP extrusion was beneficial to the ductility of the alloy. With increase of the extrusion pass, the elongation increased from 17% to 27%. However, the ultra-fine grains formation was detrimental to corrosion resistance. For the corrosion rate, compared with the without ECAP extruded samples, the corrosion resistance of the ECAP extruded samples obviously decreased.