Creep Behavior of a 4.5%Re/3.0%Ru Containing Single Crystal Nickel-based Superalloy at Elevated Temperature

• Main Authors: SHU De-long, TIAN Su-gui, WU Jing, ZHANG Bao-shuai, LIANG Shuang
• Format: Article
• Language: zho
• Published: Journal of Materials Engineering 2017-03-01
• Series: Journal of Materials Engineering
• Subjects: single crystal nickel-based superalloy; re/ru; high temperature creep property; fracture mechanism
• Online Access: http://jme.biam.ac.cn/CN/Y2017/V45/I3/41

The creep behavior of a containing 4.5%Re/3.0%Ru single crystal nickel-based superalloy at elevated temperatures was investigated by means of creep properties measurement and microstructure observations to specimens in different creep stages by SEM and TEM. Results show that the alloy exhibits good creep resistance at high temperature, and the creep life of the alloy at 1040℃/160MPa reaches 725h. During creep at high temperature, the γ' phase in alloy transforms into the N-type rafted structure along the direction vertical to the stress axis, the deformation mechanism of alloy during steady state creep is dislocations slipping in γ matrix and climbing over the rafted γ' phase. In the latter period of creep, the deformation mechanism of alloy is dislocations slipping and shearing into the rafted γ' phase. The alternate slipping of dislocations results in the twist of the rafted γ' phase to promote the initiation and propagation of the cracks along the interfaces of γ/γ' phases up to creep fracture, which is thought to be the fracture mechanism of alloy during creep at high temperature.