采用“T”型热裂模具研究了不同Cu含量对Mg-7Zn-xCu-0.6Zr (x=0、1、2、3)合金热裂行为的影响。利用XRD和SEM对Mg-7Zn-xCu-0.6Zr (x=0、1、2、3)合金进行了显微组织和热裂区域组织形貌观察。通过测量热裂纹体积表征了Mg-7Zn-xCu-0.6Zr (x=0、1、2、3)合金的热裂倾向性。实验结果表明,Mg-7Zn-xCu-0.6Zr (x=0、1、2、3)合金中随着Cu含量的增加,晶粒得到细化,晶界上的共晶相增多,共晶相在凝固末期对分离的枝晶起到补缩的作用,降低合金热裂倾向性。研究表明,Mg-7Zn-xCu-0.6Zr (x=0、1、2、3)合金微观裂纹的形成是液膜、凝固收缩补偿和晶间搭桥共同作用的结果。
As one of the highest temperature magnesium alloys, Mg-Zn-Cu ternary alloys are draw much attention in recent years. However, the previous investigations were mainly focused on their microstructure and mechanical properties. The investigations on their solidification and hot tearing behaviors are barely discussed. In order to improve the industrial applications of Mg-Zn-Cu alloy, it is necessary to better understand the solidification pathways, phase constituent and hot tearing susceptibility (HTS) of these alloys. In this work, the effect of Cu additions on the hot tearing behaviors of Mg-7Zn-xCu-0.6Zr (x=0, 1, 2, 3) alloys was studied using with T type hot tearing mold. The microstructure and the morphology of cracking zone of Mg-7Zn-xCu-0.6Zr (x=0, 1, 2, 3) alloys were observed by XRD and SEM, respectively. The hot cracking susceptibility of Mg-7Zn-xCu-0.6Zr (x=0, 1, 2, 3) alloys were characterized by the measurement of crack volume. The experimental results show that the grain sizes of Mg-7Zn-0.6Zr alloys were refined by addition of Cu element. Meanwhile, the amount of eutectic phase was increased with increasing the Cu content and the separated dendritic was refilled by the eutectic phase. Hot tearing susceptibility of Mg-7Zn-0.6Zr was decreased with increasing of Cu content. The Mg-7Zn-0.6Zr and Mg-7Zn-1Cu-0.6Zr alloys were completely broken. The hot cracks of Mg-7Zn-xCu-0.6Zr (x=0, 1, 2, 3) alloys were formed by liquid film, solidification shrinkage and interdendritic bridge.
参考文献
| [1] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%