摘要
采用显微组织观察和JMat Pro相平衡计算和热力学模拟软件等手段研究了一种实验Ni_3Al基单晶高温合金的显微组织和1100℃/90 MPa条件下的持久高塑性变形行为,并分析了持久高塑性变形机制。实验Ni_3Al基单晶合金为γ/γ'两相组织,热处理后合金枝晶干部位γ'相的体积分数为86.0%,其形貌呈接近立方体形。JMat Pro软件在平衡相析出、γ/γ'相点阵常数和γ/γ'点阵错配度方面的计算结果与实验结果吻合的较好。合金1100℃/90 MPa的平均伸长率为148.5%,平均断面收缩率为72.3%。合金在持久变形过程中形成平行于应力轴方向的P型近似筏排组织使位错易于滑移传递从而在高温持久条件下表现出高塑性变形行为。
Microstructure,high plasticity deformation behavior and mechanism of an experimental Ni3Al-based single crystal superalloy under stress-rupture condition at 1100 ℃ and 90 MPa were investigated by microstructural observation and JMat Pro numeric simulation.There are γ phase and γ＇ precipitates in the alloy.The volume fraction of nearly cubical γ＇ precipitates in the dendrite core of the alloy after heat treatment is 86.0%.The simulation results of equilibrium phase precipitation,lattice misfit of γ and γ＇ phases as well as γ / γ＇lattice misfit show good agreement with the experimental results.The average elongation percentage of the superalloy is 148.5% and the average percentage reduction in area is 72.3% at 1100 ℃ and 90 MPa.A P type nearly-rafted structure parallel to the stress axis forms during stress-rupture deformation.The dislocations can slip through freely and result in the high plasticity deformation behavior.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2016年第6期33-37,共5页
Transactions of Materials and Heat Treatment
基金
国家高技术研究发展计划(2012AA03A511)
北京市科技计划重大项目(Z131100006413005)
航空科学基金(2015ZE21006)
关键词
NI3AL
单晶高温合金
显微组织
持久变形
高塑性
Ni3Al
single crystal superalloy
microstructure
stress-rupture deformation
high plasticity
