单晶镍基高温合金超高温蠕变期间的变形机制  

Deformation Mechanism of Single-Crystal Nickel-based Superalloys During Ultra-High-Temperature Creep

作　　者：赵国旗 田素贵[1] 刘丽荣[1] 田宁 晋芳伟 Zhao Guoqi;Tian Sugui;Liu Lirong;Tian Ning;Jin Fangwei(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China;School of Mechanical Engineering,Guizhou University of Engineering Science,Bijie 551700,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870 [2]贵州工程应用技术学院机械工程学院,贵州毕节551700

出　　处：《稀有金属材料与工程》2022年第1期52-59,共8页Rare Metal Materials and Engineering

基　　金：Science and Technologyof Guizhou Province (qiankehejichu[2020]1Y198, qiankehezhicheng[2019]2870);Projects of Liaoning Natural Science Foundation (2020-Ms-212);Science and Technology Project of Bijie City (bikehezi[2019]2);Characteristic Key Laboratory of University of Guizhou Province (qianjiaohe KYzi[2019]053)。

摘　　要：通过蠕变性能测试及组织形貌观察,研究了6%Re-5%Ru(质量分数)单晶镍基高温合金的超高温蠕变行为和变形机制。结果表明,该合金在1160℃/120 MPa条件下的蠕变寿命为206 h。稳态蠕变期间,位错在基体中滑移和攀移越过筏状γ′相是合金的变形特征,基体中溶解的高浓度难熔元素可增加位错运动阻力。蠕变后期,切入筏状γ′相的位错可由{111}面交滑移至{100}面,形成Kear-Wilsdorf(K-W)位错锁,高数量K-W位错锁可抑制位错滑移和交滑移,是合金具有较好蠕变抗力和较低应变速率的原因。交滑移可扭曲筏状γ′相,并在两相界面发生裂纹萌生与扩展,直至断裂,这是合金蠕变后期的变形与损伤特征。其中,溶入γ′相的Ru原子可替换Al原子,合金中Ru与Re、W的相互作用使较多的Re、W原子溶入γ′相,延缓元素扩散速率,阻碍位错运动,使合金在超高温蠕变期间仍保留高数量K-W位错锁及良好蠕变抗力。The creep behavior and deformation mechanism of the nickel-based single-crystal superalloy containing 6 wt% Re and 5 wt% Ru at ultra-high temperatures were studied via microstructure observation and creep property analysis. The results show that under the condition of 1160 ℃/120 MPa, the Ni-based superalloy has a creep life of 206 h. During the steady state creep period, the deformation mechanism is dominated by dislocation glide in the γ matrix and dislocation climb over the γ′ raft phases. The refractory elements dissolved in the γ matrix can improve the resistance to dislocation movement. In the late creep stage, the cross-slip occurs from {111} plane to the {100} plane with the dislocations used for shearing the γ′ phase, and then the Kear-Wilsdorf(K-W)dislocation locks are formed. A large number of K-W dislocation locks can inhibit the dislocation glide and cross-slip, thus improving the creep resistance and reducing the strain rate for Ni-based superalloys. In the late creep stage, the cross-slip dislocations are initiated to twist the γ′/γ raft phases, and the crack initiation and propagation occur in the γ′/γ interfaces until fracture. These phenomena are the damage and fracture features of the Ni-based superalloys. The Ru atoms dissolved in the γ′ phase can replace the Al atoms. When Ru, Re, and W atoms react in the Ni-based superalloy, more Re and W atoms can be dissolved into the γ′ phase,which reduces the element diffusion rate and hinders the dislocation movement, thereby retaining more K-W dislocation locks and excellent creep resistance of Ni-based superalloys at ultra-high temperatures.

关 键 词：单晶镍基合金 6.0%Re-5.0%Ru 蠕变 变形机制 K-W位错锁 

分 类 号：TG132.3[一般工业技术—材料科学与工程]