ABSTRACT

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.

摘要

严重的塑性变形，如等通道角挤压 (ECAP) 会改变镁合金的机械和耐腐蚀性能。在这项工作中，研究了 ECAP 挤压对挤压 Mg-1.5Zn-0.5Y-0.5Zr 合金的机械和生物降解性能的影响。经过两道和四道 ECAP 挤压后，研究了微观结构、机械性能和降解行为。结果表明，随着挤压道次的增加，合金的平均晶粒尺寸大大减小。四道次挤压后，晶粒尺寸约为 1.37 ± 0.22 μm。ECAP 挤压有利于合金的延展性。随着挤压道次的增加，伸长率从 17% 增加到 27%。然而，超细晶粒的形成不利于耐腐蚀性。对于腐蚀速率，