摘要
通过热分析、X射线衍射、扫描电镜、透射电镜等手段分析了Mg-9Gd-4Y-0.6Mn合金的微观组织,并在室温到400℃的温度区间进行力学拉伸试验。结果表明合金在400℃时产生的超塑性现象,伸长率达266%,拉伸过程中出现动态再结晶协调晶界滑移的超塑性变形机制;在凝固过程中合金易偏析形成Mg3X(X为Gd和Y)相,Mg3X相用固溶处理的方法难以消除;在Cast-T5、Cast-T6、Rolled-T5和Rolled-T6的四种热处理状态中,Rolled-T5态的硬度最高,达121HV10;沿棱柱面析出的高密度板状析出相能有效地阻碍镁基面上的位错滑移,这是合金强化和耐热的主要原因。
The microstructure of Mg-9Gd-4Y-0.6Mn alloy was investigated by differential scanning calorimetry, X-ray diffraction, scanning electron microscopy,transmission electron microscopy and its mechanical properties were examined by tensile tests at temperatures from 25 to 400℃. The results show that this alloy has excellent mechanical properties. The superplasticity of the alloy is observed in tensile test at 400℃ and the elongation reachies 266%, and the superplastic deformation mechanism is the coordination between dynamic recrystallization and grain boundary sliding. Mg3 X（X is Gd and Y） phase easily forms in the process of solidification that can not be eliminated by solution treatment. As for the peak hardness of the alloy in the state of cast-T5 ,cast-T6,rolled-T5 and rolled-T6,the highest is obtained for rolled-T5. The high density of precipitate plates providing the effective barriers to dislocations gliding on the basal plane of magnesium is the cause of strengthening and heat resistance of this alloy.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2007年第2期44-48,共5页
Transactions of Materials and Heat Treatment
基金
国家"863"计划资助项目(2005AA741062
2004AA741062)
国家科研项目(5133001E)和(51412020304QT7106)
关键词
Mg-Gd-Y-Mn合金
耐热
组织
力学性能
超塑性
Mg-Gd-Y- Mn alloy
heat-resistant
microstructure
mechanical properties
superplasticity
