(1. 河南科技大学 材料科学与工程学院，洛阳 471023；
2. 有色金属共性技术河南省协同创新中心，洛阳 471023)
摘 要: 研究挤压温度对铸态Mg-2.0Zn-0.5Zr-3.0Gd生物镁合金组织、力学性能及耐腐蚀性能的影响。结果表明：挤压温度在330~350 ℃时，动态再结晶的体积分数随挤压温度的升高而增加；在350~370 ℃时，动态再结晶的体积分数随温度的升高而降低。挤压态合金的析出相主要由纳米级的棒状(Mg, Zn)3Gd相和新析出的颗粒状Mg2Zn11相组成。合金的力学性能与动态再结晶晶粒的体积分数成正比关系。挤压温度为350 ℃时，合金的抗拉强度、屈服强度及伸长率分别为(247±3) MPa、(214±3) MPa和(26.7±1.1)%。随着挤压温度的升高，合金的腐蚀速率先减小后增大，挤压温度为350 ℃时，合金的静态腐蚀速率及析氢腐蚀速率分别为0.614 mm/a和0.598 mm/a。
关键字: 镁合金；微观组织；生物腐蚀性能；力学性能
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of Nonferrous Metals, Luoyang 471023, China）
Abstract:Effects of the extrusion temperature on the microstructure, mechanical properties and corrosion resistance of as-cast Mg-2.0Zn-0.5Zr-3.0Gd biomedical magnesium alloy were investigated. The experimental results show that the volume fraction of dynamic recrystallized (DRXed) microstructure increases with increasing the extrusion temperature from 330 ℃ to 350 ℃, but decreases as the temperature increased further to 370 ℃. The precipitated phases of extruded alloys are composed of nanoscale rod-like (Mg, Zn)3Gd and granular Mg2Zn11 phase. The Mg2Zn11 precipitated phase is a new precipitated phase in the extrusion process. The mechanical properties of extruded alloys are proportional to the volume area fraction of the DRXed grains. When the extrusion temperature is 350 ℃, the ultimate tensile strength, yield strength and ultimate tensile strength of extruded alloys are (248±3) MPa, (228±3) MPa and (29.4±0.9) %, respectively. The corrosion rates of the extruded alloys decrease initially and then increase with increasing the extrusion temperature from 330 ℃ to 370 ℃. The corrosion rates of the alloy were determined to be 0.614 mm/a and 598 mm/a, respectively, in mass loss and hydrogen evolution methods when the extrusion temperature is 350 ℃.
Key words: magnesium alloy; microstructure; biocorrosion property; mechanical property
