Abstract

Microstructure, texture characteristics, mechanical and bio-corrosion properties of the Mg–5Zn–xSr alloys (x = 0, 0.2, 0.6, 1.0) prepared by high strain rate rolling are carefully studied. A low level of Sr addition enhances dynamic precipitation of nano-scale MgZn₂ particles in the as-rolled Mg–5Zn alloy, with 0.6%Sr showing the maximum efficiency. These high-density MgZn₂ particles can pin grain boundaries of dynamic recrystallization grains and inhibit their growth. A low level of Sr addition (≤ 0.6%) enhances the (0002) basal texture, but 1.0%Sr is just the reverse. The as-rolled Mg–5Zn–0.6Sr alloy exhibits the best combination of ultimate tensile strength (359 MPa) and elongation to rupture (20%). The high strength can be attributable to a reduced grain size, precipitation and basal texture strengthening. The Mg–5Zn–xSr alloys exhibit excellent bio-corrosion resistance, but a minor Sr addition cannot bring about further bio-corrosion resistance improvement due to the multiple actions of grain size, DRX degree, dynamic precipitates and texture characteristics. The 0.6%Sr addition can greatly improve the strength of the as-rolled alloy at no expense of bio-corrosion resistance.

Graphic Abstract

中文翻译：

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高应变率轧制 Mg-Zn-Sr 合金的显微组织、织构特征、机械和生物腐蚀性能

摘要

仔细研究了通过高应变率轧制制备的 Mg-5Zn-xSr 合金 (x = 0, 0.2, 0.6, 1.0) 的显微组织、织构特征、机械和生物腐蚀性能。低水平的 Sr 添加增强了轧制态 Mg-5Zn 合金中纳米级 MgZn ₂颗粒的动态沉淀，0.6% Sr 显示出最大的效率。这些高密度 MgZn ₂颗粒可以钉住动态再结晶晶粒的晶界并抑制它们的生长。低水平的 Sr 添加 (≤ 0.6%) 可增强 (0002) 基础织构，但 1.0% Sr 正好相反。轧制后的 Mg-5Zn-0.6Sr 合金表现出极限抗拉强度 (359 MPa) 和断裂伸长率 (20%) 的最佳组合。高强度可归因于晶粒尺寸减小、沉淀和基础织构强化。Mg-5Zn-xSr合金表现出优异的抗生物腐蚀性能，但由于晶粒尺寸、DRX度、动态析出物和织构特征的多重作用，少量的Sr添加不能带来进一步的抗生物腐蚀性能。添加0.6%Sr可以在不牺牲抗生物腐蚀性的情况下大大提高轧态合金的强度。

图形摘要