Structure Evolution and Creep Behavior for a Nickel-Base Single Crystal Alloy along [011] and [001] Orientations

2011 ◽  
Vol 40 (9) ◽  
pp. 1522-1525 ◽  
Author(s):  
Shui Li ◽  
Peng Zheng
2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Lei Li ◽  
Liangbo Ao ◽  
Gongnan Xie ◽  
Xinmei Wang ◽  
Gang Cao

Film cooling technology is developed to enhance the temperature resistant of nickel-base single crystal alloy blade. The shape, dimension, and arrangement of cooling holes impact the blade strength and life grievously. In this paper, the influences of holes arrangement on creep characteristic of cooling holes in the plate sample are investigated. The constitutive model for creep considering both cavitation and degradation damage is developed to predict the creep behavior of cooling holes. Results show that there are stress interferences among cooling holes. The distance and radius of the cooling holes impact the creep behavior of cooling holes seriously. Decreasing horizontal distance of the holes results in creep time reducing. On the contrary, increasing the vertical distance of the holes makes the creep time reduced.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Liwu Jiang ◽  
Yu Yang ◽  
Meiling Wu ◽  
Min Cai

The creep behaviors of Ni3Al-based single crystal alloy IC6SX with [001] and [111] orientations under the condition of 850°C/450 MPa were investigated. The effect of crystal orientation on the creep lives, fracture morphology, fracture mechanism, and dislocation evolution of the alloys with different orientations was analyzed systematically. The results showed that the creep lives of the alloy were closely related to the crystal orientation under the condition of 850°C/450 MPa. The creep lives of the single crystal alloys with [001] and [111] orientations were 56.3 h and 126.9 h, respectively. Moreover, the fracture morphologies of the two alloys with [001] and [111] orientations were different. The results showed that some holes formed at the fracture surface of the alloy with [111] rather than [001] orientation. Furthermore, the surface near the fracture of the two alloys with [001] and [111] orientations was serrated. Therefore, the fracture mechanism of the single crystal alloys with [001] and [111] orientations was ductile fracture. In addition, a large number of dislocations cut into the γ ′ phase. Therefore, the cutting mechanism of dislocations in the alloys with [001] and [111] orientations was the creep deformation mechanism.


2011 ◽  
Vol 4 (11) ◽  
pp. 3696-3700
Author(s):  
Yong Su ◽  
Sugui Tian ◽  
Huichen Yu ◽  
Jun Xie ◽  
Lili Yu ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Liwu Jiang ◽  
Xuezheng Dou ◽  
Meiling Wu

Ni3Al-based single crystal alloy IC6SX was prepared by seed crystal method. The effect of different stress conditions on creep behavior of this alloy at 980°C was investigated. The results showed that the creep life of this alloy at 980°C decreased significantly with the increase of stress. When the stress increased from 180 MPa to 230 MPa, the creep life dropped from 245.5 h to 69.3 h, and the steady-state creep rate increased slightly but not significantly. Meanwhile, the morphology of γ ′ phase and dislocation after creep were studied. The results showed that with the increase of stress, the density of dislocations in the γ ′ phase increased gradually, the strength of this alloy decreased gradually, so the creep life decreased significantly. The Y-NiMo phase resolved from the γ phase decreased gradually as the creep life decreased. The creep experiment of the alloy was carried out at 980°C. Due to the higher temperature, the diffusion of atoms in this alloy became faster. Deformation was not only caused by the slippage of dislocations in the crystal but also by the diffusion of atoms. Therefore, the creep mechanism of single crystal alloy IC6SX at this temperature is a mixed mechanism of dislocation glide and diffusion.


2005 ◽  
Vol 475-479 ◽  
pp. 623-626 ◽  
Author(s):  
Yuichiro Koizumi ◽  
Hiroshi Harada

The creep behavior and microstructure of several nickel-base single-crystal superalloys after high-temperature low-stress creep have been investigated. These alloys were designed with varying content of the alloying elements Mo and Ru. At 1100°C and 137 MPa, the large g/g¢ lattice misfit in negative with the addition of Mo leads to the formation of dense interfacial dislocation networks. These dislocation networks are effective to strengthen the alloys during creep by preventing the penetration of the g dislocations into the g¢ phase.


2015 ◽  
Vol 816 ◽  
pp. 551-556
Author(s):  
Su Gui Tian ◽  
Bao Shuai Wang ◽  
Xin Ding ◽  
De Long Shu ◽  
Jing Wu

Creep behavior of a heat treated single crystal nickel base superalloy containing Re/Ru under the test condition of 1100°C/137MPa high temperatures was investigated. The experimental results showed that the segregation extent of elements in the dendrite and inter-dendrite regions of single crystal superalloy decreases by heat treatment at high temperature. The creep life of the alloy at 1100°C/137MPa was measured to be 321 h displaying a better creep resistance. Wherein, significant amount of fine cubiodal γ′ particles precipitated in the γ matrix channels are considered to be the main reason of the alloy having the better creep resistance. The deformation feature of the alloy during steady state creep is dislocations slipping in the γ matrix and climbing over the rafted γ′ phase. But in the latter stage of creep, the deformation feature of the alloy is dislocations shearing into the rafted γ′ phase. As creep goes on, the main / secondary slipping dislocations in the alloy are alternately activated to result in the initiation and propagation of the cracks along the interface of the rafted γ′/γ phase up to fracture, which is thought to be the fracture mechanism of the alloy during creep.


Sign in / Sign up

Export Citation Format

Share Document