摘要
通过对合金进行不同温度层错能的计算、蠕变性能测试及位错组态的衍衬分析,研究温度对单晶镍基合金层错能和蠕变机制的影响。结果表明:合金在760℃具有较低的层错能,其蠕变期间的变形机制是〈110〉超位错剪切进入γ′相,其中,切入γ′相的位错可分解形成(1/3)〈112〉位错+(SISF)层错的位错组态。随温度的提高,合金的层错能增大,合金在1070℃蠕变期间的变形机制是〈110〉螺、刃超位错剪切进入γ′相。在980℃,合金的层错能介于760~1070℃之间,蠕变期间的主要变形机制是〈110〉螺、刃超位错剪切进入γ′相,其中,剪切进入γ′相的螺位错由{111}面交滑移至{100}面,形成(1/2)〈110〉不全位错+反向畴界(APB)的K-W锁位错组态,这种具有面角非平面芯结构的K-W锁可抑制位错的交滑移,提高合金的蠕变抗力。其中,蠕变期间较低的应变速率仅释放较少的形变热,不足以激活K-W锁中的位错在{111}面滑移,是K-W锁在980℃得以保留的主要原因。
By means of calculating stacking fault energy(SFE),measuring creep properties and contrast analysis of dislocation configuration,the influence of the temperature on the stacking fault energy and the creep mechanism of a single crystal nickel-based superalloy was investigated.Results show that there is a lower stacking fault energy(SFE)of the alloy at 760℃,and the deformed mechanism of the alloy during creep is the cubicalγ′phase sheared by〈110〉super-dislocation which may be decomposed to form the configuration of(1/3)〈112〉super-Shockley partials dislocation plus the super-lattice intrinsic stacking fault(SISF).But the stacking fault energy of the alloy increases with temperature,so the deformed mechanism of the alloy during creep at 1070℃is the screw or edge super-dislocation shearing into the raftedγ′phase.The SFE of the alloy at 980℃is in the middle value of the SFEs between 760℃and 1070℃,the main deformed mechanism of the alloy during creep is the screw or edge super-dislocation shearing into the raftedγ′phase.And some super-dislocation shearing intoγ′phase may cross-slip from{111}to{100}planes to form the K-W locks configuration of(1/2)〈110〉partials plus the anti-phase boundary(APB).The K-W locks with non plane core structure may restrain the slipping and cross-slipping of dislocations to improve the creep resistance of alloy.Wherein,the lower strain rate during creep releases too less deformed heat to activate the dislocation in the K-W locks for re-slipping on{111}plane,which is thought to be the main reason of the K-W locks kept in the alloy during creep at 980℃.
作者
闫化锦
田素贵
朱新杰
于慧臣
舒德龙
张宝帅
YAN Hua-jin;TIAN Su-gui;ZHU Xin-jie;YU Hui-chen;SHU De-long;ZHANG Bao-shuai(School of Mechanical Engineering,Guizhou University of EngineeringScience,Bijie 551700,Guizhou,China;School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China;Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation, AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2018年第10期87-95,共9页
Journal of Materials Engineering
基金
国家自然科学基金资助项目(51271125)
关键词
单晶镍基合金
层错能
蠕变
衍衬分析
变形机制
single crystal nickel-base superalloy
stacking fault energy
creep
contrast analysis
deformation mechanism
