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将固溶处理后的Mg-2.7Nd-0.6Zn-0.5Zr合金在200~300℃之间进行不同温度及时间的高温时效处理,研究高温短时间时效处理对合金的微观组织和力学性能的影响,并利用OM,SEM和TEM对合金的微观组织进行表征.结果表明,固溶态Mg-2.7Nd-0.6Zn-0.5Zr合金经250~275℃高温短时间时效后,其室温屈服强度和抗拉强度最高分别增加了近70%和29%,宏观组织中出现呈直线性不均匀分布的析出相.析出相的显微形貌为颗粒状,成分为Mg12Nd.析出相的线性分布方向平行于Mg基体(0001)Mg基面,合金的时效硬化行为与这种沿基面呈平行线分布的颗粒状析出相密切相关.在250~275℃范围内时效20~30 min后屈服强度较高,这是由于在变形过程中颗粒状Mg12Nd的特殊分布对基面滑移及晶粒间协调变形起到很强的抑制作用.
The microstructure and mechanical properties of Mg-2.7Nd-0.6Zn-0.5Zr alloy after solution treatment at high temperature and for a short time at different temperature and time were studied at 200 ~ 300 ℃. , And the microstructure of the alloy was characterized by OM, SEM and TEM.The results show that the room temperature yield strength and resistance of Mg-2.7Nd-0.6Zn-0.5Zr alloy after aging at 250-275 ℃ for short time, The maximum tensile strength increased by nearly 70% and 29% respectively, and the precipitates appeared linearly and unevenly distributed in the macrostructure.The precipitated phase was granular and the composition was Mg12Nd.The linear distribution of precipitates was parallel to The Mg-based (0001) Mg matrix and the age-hardening behavior of the alloy are closely related to the grain-like precipitates distributed along the parallel lines along the basal plane.The yield strength is higher after aging at 250-275 ℃ for 20-30 min, This is due to the special distribution of granular Mg12Nd during the deformation of the base surface sliding and intergranular coordination deformation played a strong inhibitory effect.