挤压温度对Mg-3Al-3Ca-0.5Mn镁合金组织及拉伸性能的影响

Effect of extrusion temperature on microstructure and tensile property of as-extruded Mg-3Al-3Ca-0.5Mn alloy

本文以Mg-3Al-3Ca-0.5Mn合金为研究对象,研究了在相同挤压比(挤压比为61),不同挤压温度(300℃、350℃、400℃)下制备的热挤压成型棒材的组织及力学性能。结果表明:较低的挤压温度(300℃)下,合金晶粒由等轴晶转变为混晶组织,合金的抗拉强度和屈服强度逐渐降低,但是延伸率显著提高。挤压温度为300℃时,动态再结晶不完全,合金中的第二相存在团簇现象,合金具有最佳的抗拉强度和屈服强度,分别为424MPa和393MPa;随着挤压温度升高到400℃时,动态再结晶更加完全,第二相呈弥散均匀分布,合金延伸率为12.7%。

The influence of different extrusion temperature（ 300℃,350℃,400℃） on the microstructure and mechanical properties of Mg-3Al-3Ca-0.5Mn alloy were studied at extrusion ratio（ 61）. The results showed that,with the decreasing of extrusion temperature,the grains structure of the alloy changed from equiaxed to mixed crystal structure,the tensile strength and yield strength decreased,but the elongation rate increased significantly under300℃ extrusion temperature. There existed the cluster phenomenon of second phase and incomplete dynamic recrystallization at 300℃,where the ultimate strength and yield strength were 424 MPa,393 MPa,respectively. When the extrusion temperature increased to 400℃,the distribution of second phase was more homogeneous dispersion and the dynamic recrystallization was more complete,where the elongation was 12. 7%.