ZTM630镁合金双级时效实验研究

Experimental study on two-stage aging treatment of ZTM630 magnesium alloy

通过改变Mg-6Zn-3Sn-0.5Mn合金终时效时间,利用金相显微镜、扫描显微镜、透射电子显微镜观察挤压态ZTM630合金在双级时效后的微观组织特征。结果表明,该合金比较适宜的双级时效参数为90℃×12 h+180℃×8 h,在该参数下合金的抗拉强度、伸长率分别为383.1 MPa、7.667%。双级时效之后,在基体与晶界处都有弥散细小的析出相析出,主要为Mg_2Sn、MgZn_2相化合物。在拉伸过程中弥散细小析出相的析出强化作用和阻碍晶粒移动产生的强化作用,使得合金的力学性能更优。

By changing the final-aging time,the microstructure evolution and mechanical properties of extruded Mg-6 Zn-3 Sn-0. 5 Mn alloy were investigated by means of optical electron microscopy, scanning electron microscopy and transmission electron microscopy. Results showed that through the two-step aging treatment,the suitable parameter was90 ℃×12 h＋180 ℃×8 h. Under this parameter,ultimate tensile strength and elongation of the alloy reached 383.1 MPa,7.667%,respectively. After two-step aging treatment,there were dispersed and fine precipitates precipitated in matrix and grain boundaries,which were mainly of Mg2Sn and MgZn2 phases. During the process of stretching,the precipitation strengthen effect of dispersed fine precipitated phase and the strengthening effect inhibiting the grain movement made the mechanical properties of the alloy better.