利用光学显微镜、扫描电子显微镜、透射电子显微镜、失重测试、电化学测试与拉伸试验研究热挤压与退火温度对Mg-Zn-Zr-Ce生物镁合金组织与性能的影响.结果表明:热塑性变形后合金发生动态再结晶,合金的组织由细小的再结晶晶粒与未再结晶的晶粒组成;退火后变形晶粒发生再结晶,随着退火温度的升高,晶粒逐渐长大.当退火温度高于200℃时,合金的腐蚀电流密度(Jcorr)与平均晶粒尺寸(d)满足J corr=a+bd?1/2方程.由该方程可推测出经200 ℃退火3 h后,合金的腐蚀电流密度最低,合金的综合性能最好,抗拉强度与伸长率分别达到245.8 MPa和16.2%,腐蚀速率为0.7235 mm/a.%The effects of hot extrusion process and annealing temperature on the microstructure and properties of Mg-Zn-Zr-Ce biomedical alloy were investigated by OM (Optical microscope), SEM (Scanning electron microscope), TEM (Transmission electron microscope), immersion test, electrochemical measures and tensile tests. The result shows that dynamic recrystallization occurs during hot plastic deformation, and the microstructure of extruded alloy is consisted of fine DRXed (Dynamic recrystallized) grain and unDRXed grain. The recrystallization occurs in deformed grains and the recrystallized grains grow subsequently after annealing treatment. When annealing temperature is over 200℃, the corrosion current (J corr) and grain size (d) meet the following equation: J corr=a+bd?1/2. According to the equation, it concludes that the alloy annealed at 200 ℃ for 3 h possesses the lowest corrosion current, and exhibits the optimized comprehensive properties. The elongation, tensile strength and corrosion rate are about 16.2%, 245.8 MPa and 0.7235 mm/a, respectively.
展开▼
