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利用OM、SEM、质量损失测试、电化学测试与拉伸试验研究了挤压温度对Mg-2Zn-0.4Zr-0.6Ce生物镁合金组织与性能的影响.结果表明,热挤压后合金发生动态再结晶,合金的组织均由细小的再结晶晶粒与原始晶粒组成.在470～510℃范围内随着挤压温度的升高,合金再结晶晶粒体积分数逐渐增大,晶粒尺寸变化不明显,合金的腐蚀速率与腐蚀电流密度Ic..先减小后增大,容抗弧半径先增大后减小.挤压温度为490℃时,合金的耐蚀性最好,腐蚀速率为0.9337 mm.a-1,腐蚀电流密度为4.67 μA·cm-2.由于细晶强化与位错强化作用,热挤压后合金的强度得到提高,随着挤压温度的升高,合金的抗拉强度和伸长率先增大后减小.挤压温度为490℃时,合金的综合力学性能最好,合金的抗拉强度与伸长率分别为259.1 MPa与14.1％.

The effects of extrusion temperature on microstructure and properties of Mg-2Zn-0.4Zr-0.6Ce biomedical magnesium alloy were studied by means of OM,SEM,immersion test,electrochemical test and tensile test.The result shows that dynamic recrystallization occurs during hot extrusion,and the microstructure of the extruded alloy is composed of fine dynamic recrystallized (DRXed) grain and as-received grain.When the extrusion temperature increases in the range of 470-510 ℃,the volume fraction of DRXed grain gradually increases,and there is no obvious change in grain size,and while the corrosion rate and corrosion current density (Icorr) of the alloy decrease and then increase,the capacitive arc diameter increases and then decreases.When extrusion temperature is 490 ℃,the corrosion resistance is optimized,and the corrosion rate and corrosion current density (Icorr) are 0.9337 mm· a-1 and 4.67 pA· cm-2,respectively.Because of refinement strengthening and dislocation strengthening,the tensile strength of the extruded alloy is enhanced.With the extrusion temperature increasing,the tensile strength and elongation of the alloy both increase and then decrease.When extrusion temperature is 490 ℃,the alloy exhibits the optimized comprehensive mechanical properties,in which the tensile strength and elongation are 259.1 MPa and 14.1％,respectively.