利用光学显微镜、X射线衍射和扫描电镜等对挤压态和时效态Mg-6Zn-1Mn-4Sn和Mg-6Zn-1Mn-4Sn-0.5Y镁合金的微观组织和力学性能进行研究。结果表明:与ZMT614镁合金相比,添加Y元素后,ZMT614-0.5Y晶粒得到细化,综合力学性能得到提高。Mg-6Zn-1Mn-4Sn-0.5Y合金的相组成为α-Mg、Mg Zn2、Mn、Mg2Sn和MgS n Y相。经过T6热处理后,合金的抗拉强度和屈服强度明显得到提高,伸长率明显被降低。理论计算表明,在挤压态合金中,细晶强化和固溶强化产生重要的作用,而在T6热处理态合金中,析出强化产生决定作用。
Optical microscope(OM),scanning electron microscope(SEM),transmission electron microscope(TEM)and tensile machine were used to characterize the microstructures and mechanical properties of as-forged and aged Mg-9.5Gd-3.8Y-0.6Zr alloys.The results show that a novel kind of dislocation arrays,comprising parallel arranged dislocations,were obtained in the forged alloy.The arrays tend to extend parallel and are heterogeneously distributed with adjacent distances varying from 0.3μm to 1.4μm.After aging the alloy at 265°C,a large number of preferential-oriented phases were precipitated on the dislocation arrays,forming a structure of"precipitation chains"(PCs),which results in simultaneous increments of strength and ductility.
Chao YouChurning LiuYingchun WanBei TangBizheng WangYonghao GaoXiuzhu Han
