【摘要】 利用光学显微镜和扫描电镜对AZ31镁合金挤压板再结晶退火前后的显微组织和断口形貌进行分析,并通过室温拉伸试验研究了再结晶退火前后的力学性能。结果表明,随退火保温时间的延长,板材先出现大量片状退火孪晶,随后退火孪晶消失,变形组织被细小、均匀的再结晶晶粒所取代;再结晶退火后,挤压板伸长率增加,抗拉强度提高;退火后试样断裂时宏观断口呈现撕裂棱与韧窝共存的形貌,呈韧性断裂,且随着合金晶粒尺寸减小,撕裂棱和韧窝更加细小。更多还原

【Abstract】 The microstructure,fracture appearance and mechanical properties of AZ31 magnesium alloy extrusion sheet before and after recrystallization annealing were studied by means of optical microscope(OM),scanning electron microscope(SEM) and tension test at ambient temperature.The results show that with the annealing time prolonging,the lamellar annealing twins occur at first and then disappear,and deformation microstructure is displaced by the fine and uniform recrystallization grains.Elongation and tensile strength are improved evidently after recrystallization annealing.Tear corners and dimples are coexistent in fracture appearance and their sizes are much finer with reducing of crystal grain size,and the fracture mechanism is ductile character.更多还原