摘要
本工作研究了Mg-11Gd-2Y-1.5Ag-0.5Zr合金在225~275℃/110~150 MPa条件下的高温蠕变行为和组织演变。结果表明:合金在225℃/110~150 MPa蠕变状态下,蠕变应力指数n=3.4,蠕变机制为位错滑移机制;在250℃/110~150 MPa蠕变状态下,蠕变应力指数n=4.7,蠕变机制为位错滑移机制;在275℃/110~130 MPa蠕变状态下,蠕变应力指数n=5.8,蠕变机制为位错滑移机制;在275℃/130~150 MPa蠕变状态下,蠕变应力指数n=10.5,幂律蠕变定律失效,蠕变机制较为复杂。根据蠕变激活能Q值对蠕变机制的分析结果与蠕变激活能n值分析结论基本一致。合金在同一温度下,晶粒尺寸随着应力的增大而增大;在同一应力下,晶粒尺寸随着温度的升高而减小。在本研究中,110~150 MPa的高应力范围内,合金在250℃以下有着良好的抗蠕变性能。
The creep behavior and microstructure evolution of Mg-11Gd-2Y-1.5Ag-0.5Zr alloy at 225—275℃/110—150 MPa were studied.The results show that the creep stress exponent n is 3.4 at 225℃/110—150 MPa,and the creep mechanism is dislocation slip mechanism.At 250℃/110—150 MPa,the creep stress exponent n is 4.7,and the creep mechanism is dislocation slip mechanism.At 275℃/110—130 MPa,the creep stress exponent n is 5.8,and the creep mechanism is dislocation slip mechanism.At 275℃/130—150 MPa,the creep stress exponent n is 10.5,the creep law of power law is invalid and the creep mechanism is complex.The results of creep activation energy Q on creep mechanism are basically consistent with the result of creep stress exponent n value.At the same temperature,the grain size increases with the increase of stress.Under the same stress,the grain size decreases with the increase of temperature.Under the high stress range of 110 MPa to 150 MPa,the alloy has good creep resistance under 250℃.
作者
关海昆
李全安
陈晓亚
张帅
王颂博
GUAN Haikun;LI Quan’an;CHEN Xiaoya;ZHANG Shuai;WANG Songbo(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第6期6126-6130,共5页
Materials Reports
基金
国家自然科学基金(51571084,51171059)。
