Deformation and Damage Features of a 4.5% Re Nickel-Based Single Crystal Superalloy during Creep at Medium Temperature

2014 ◽  
Vol 788 ◽  
pp. 459-465 ◽  
Author(s):  
De Long Shu ◽  
Su Gui Tian ◽  
Jing Wu ◽  
Zhong Ge Guo
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Stress Axis ◽  
Fracture Mechanisms ◽  
Medium Temperature ◽  
Creep Properties ◽  
Microstructure Observation ◽  
Micro Cracks ◽  
Deformation And Fracture ◽  
Main Deformation

The deformation and damage behaviors of a 4.5% Re nickel-based single crystal superalloy during creep at medium temperature were conducted by means of creep properties measurement and microstructure observation in the present investigation. The results show that the creep life of the superalloy was measured to be 226h at 820MPa/820oC, displaying a better creep resistance. After the alloy crept up to fracture, the γ′ phase in the region near fracture was contorted and coarsened, which is attributed to the severe plastic deformation. In the latter stage of creep, the main/secondary slipping systems were alternately activated to twist the γ′ and γ phases, which promoted the initiation of the cracks along the interfaces of γ′ /γ phases. And the micro-cracks may be propagated both along the direction vertical to the stress axis and along the direction of slipping traces, which is thought to be the main deformation and fracture mechanisms of the alloy in the latter stage of the creep.

Creep Behaviors of a Single Crystal Nickel-Based Superalloy Containing 4.2%Re

2011 ◽  
Vol 689 ◽  
pp. 276-281 ◽  
Author(s):  
Su Gui Tian ◽  
Ben Jiang Qian ◽  
Fu Shun Liang ◽  
An An Li ◽  
Xing Fu Yu
Keyword(s):  
Single Crystal ◽  
Applied Stress ◽  
Microstructure Evolution ◽  
Deformation Mechanism ◽  
Stress Axis ◽  
Steady Creep ◽  
Nickel Based Superalloy ◽  
Microstructure Observation ◽  
Creep Curves ◽  
Main Deformation

By the measurement of creep curves and microstructure observation, an investigation has been made into the creep behaviors and microstructure evolution of a single crystal nickel-based superalloy containing 4.2%Re. Results show that the superalloy displays an obvious sensibility on the applied temperatures and stresses in the range of the applied temperatures and stresses. During the initial creep, the cubical g¢ phase in the alloy is transformed into an N-type rafted structure along the direction vertical to the applied stress axis. After crept up to fracture, the rafted g¢ phase in the region near fracture is transformed into a twisted configuration. The dislocation climbing over the rafted g¢ phase is considered to be the main deformation mechanism of the alloy during the steady creep state, and dislocations shear into the rafted g¢ phase is the main deformation mechanism of the alloy in the later stage of creep.

Deformation Features of a High Mo Nickel-Based Single Crystal Superalloy during Creep at High Temperature

2019 ◽  
Vol 795 ◽  
pp. 35-42
Author(s):  
Hua Jin Yan ◽  
Su Gui Tian ◽  
Guo Qi Zhao ◽  
Shun Ke Zhang
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Stress Axis ◽  
Creep Properties ◽  
Nickel Based Superalloy ◽  
Damage And Fracture ◽  
Initiation And Propagation ◽  
Deformation Features ◽  
Fracture Features

The deformation and damage features of a high Mo single crystal Ni-based superalloy during creep at high temperature are investigated by means of measuring creep properties and observing microstructure. Results show that, compared to 4%Mo single crystal nickel-based superalloy, the 6%Mo superalloy displays a better creep resistance, and the creep life of 6%Mo single crystal superalloy at 1040°C/137MPa is measured to be 556 h. In the ranges of applied temperatures and stresses, the creep activation energy of the alloy is measured to be 484.7kJ/mol. Wherein, the deformation mechanisms of the 6%Mo superalloy during steady state creep are dislocations slipping in ϒ matrix and climbing over the rafted ϒ' phase. In the later stage of creep, the deformation mechanism of alloy is dislocations shearing into the rafted ϒ' phase, the alternate activation of dislocations slipping results in the twisted of the rafted ϒ'/ϒ phases, as the creep goes on, to promote the initiation and propagation of cracks along the interface of the twisted ϒ/ϒ' phase perpendicular to the stress axis, up to creep fracture, which is thought to be the damage and fracture features of the alloy during creep at high temperature.

Damage and Fracture Mechanism of a Nickel-Based Single Crystal Superalloy during Creep at Moderate Temperature

2014 ◽  
Vol 783-786 ◽  
pp. 1188-1194 ◽  
Author(s):  
Su Gui Tian ◽  
Zhong Ge Guo ◽  
De Long Shu ◽  
Jun Xie
Keyword(s):  
Single Crystal ◽  
Fracture Mechanism ◽  
Cleavage Plane ◽  
Moderate Temperature ◽  
Single Crystal Superalloy ◽  
Stress Axis ◽  
Creep Fracture ◽  
Microstructure Observation ◽  
Damage And Fracture ◽  
Secondary Cleavage

By means of creep properties measurement and microstructure observation, an investigation has been made into the damage and fracture mechanism of a nickel-based single crystal superalloy during creep at moderate temperature. Results show that the deformation mechanism of the alloy in the latter stage of creep is that the primary-secondary slipping systems are alternately activated, and the micro-crack is firstly initiated on the γ′/γ phases interface in the intersection regions of two slip systems. As creep goes on, the micro-crack is propagated along the γ′/γ interface, which is perpendicular to stress axis, to form the square-like cleavage plane on the (001) plane. Thereinto, the propagation of the cracks on (001) plane is intersected with {111} cleavage plane which is secondly activated, which may terminate the propagation of the crack to form the cleavage plane with square-like feature on (001) plane along the <110> directions. Due to the multi-cracks may be propagated on different cross-section of the alloy during creep, and the tearing edge or secondary cleavage plane are formed along the direction with bigger shearing stress at the crack tip, which makes the multi-cracks connected each other until the occurrence of creep fracture, this is thought to be the main reason of the creep fracture having the uneven and multi-level cleavage characteristics.

scholarly journals Effect of long-term thermal exposure on microstructure and creep properties of DD5 single crystal superalloy

China Foundry ◽  
2021 ◽  
Vol 18 (3) ◽  
pp. 185-191
Author(s):  
Xu-dong Wang ◽  
Zhong Yang ◽  
Qiang Gao ◽  
Li-rong Liu
Keyword(s):  
Single Crystal ◽  
Thermal Exposure ◽  
Single Crystal Superalloy ◽  
Creep Properties

A New Finite Element Simulation by Genetic Search Algorithm

2013 ◽  
Vol 791-793 ◽  
pp. 1318-1321
Author(s):  
Lei Meng
Keyword(s):  
Single Crystal ◽  
Applied Stress ◽  
Search Algorithm ◽  
Fem Analysis ◽  
Stress Axis ◽  
Direction Parallel ◽  
Genetic Search ◽  
Microstructure Observation ◽  
Element Simulation ◽  
Circular Holes

By means of measuring creep curves, microstructure observation and FEM analysis of the stress field near the hole; an investigation has been made into the influence of the defects on creep behaviors and microstructure evolution of single crystal nickel-based superalloys. Results show that the creep lifetimes and plasticity of the single crystal nickel based superalloys are obviously decreased by microstructure defects. During high temperature creep, the stress isoline near the holes region displays the feature of the acetabuliform distribution, and possesses the bigger stress value at 45° angle direction relative to the applied stress axis. That results in the γ phase transformed into the rafted structure at 45° angle direction relative to the applied stress axis, and the circular holes defects are elongated into the ellipse in shape along the direction parallel to the applied stress axis.

Creep Behavior of a 4.5% Re Nickel-Base Single Crystal Superalloy at High Temperature

2015 ◽  
Vol 750 ◽  
pp. 139-144 ◽  
Author(s):  
De Long Shu ◽  
Su Gui Tian ◽  
Xin Ding ◽  
Jing Wu ◽  
Qiu Yang Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Single Crystal ◽  
Deformation Mechanism ◽  
Creep Property ◽  
Single Crystal Superalloy ◽  
Micro Cracks ◽  
Initiation And Propagation ◽  
Temperature Ranges ◽  
Nickel Base

By means of heat treatment and creep property measurement, an investigation has made into the creep behaviors of a containing 4.5% Re nickel-base single crystal superalloy at high temperature. Results show that the elements W, Mo and Re are enriched in the dendrite arm regions, the elements Al, Ta, Cr and Co are enriched in the inter-dendrite region, and the segregation extent of the elements may be obviously reduced by means of heat treatment at high temperature. In the temperature ranges of 1070--1100 °C, the 4.5% Re single crystal nickel-based superallloy displays a better creep resistance and longer creep life. The deformation mechanism of the alloy during steady state creep is dislocations slipping in the γ matrix and climbing over the rafted γ′ phase. In the later stage of creep, the deformation mechanism of alloy is dislocations slipping in the γ matrix, and shearing into the rafted γ′ phase, which may promote the initiation and propagation of the micro-cracks at the interfaces of γ/γ′ phases up to the occurrence of creep fracture.

Effect of pre-rafting on creep properties of Ni-based single crystal superalloy

2019 ◽  
Vol 110 (6) ◽  
pp. 508-516
Author(s):  
Wenyan Gan ◽  
Zhixun Wen ◽  
Haiqing Pei ◽  
Yamin Zhang ◽  
Hangshan Gao
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Creep Properties

Influence of Environment on Creep Properties of MC2 Single Crystal Superalloy at 1150°C

2004 ◽  
Vol 461-464 ◽  
pp. 647-654 ◽  
Author(s):  
Sébastien Dryepondt ◽  
Daniel Monceau ◽  
Fabrice Crabos ◽  
Cyril Vernault
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Creep Properties

Influence of Environment on Creep Properties of MC2 Single Crystal Superalloy at 1050°C AND 1150°C

2013 ◽  
pp. 173-180 ◽  
Author(s):  
Sébastien Dryepondt ◽  
Eric Andrieu ◽  
Daniel Monceau ◽  
Fabrice Crabos ◽  
Cyril Vernault
Keyword(s):  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Creep Properties

Influence of Solution Temperature on Compositions Segregation and Creep Behavior of a Single Crystal Nickel-Based Superalloy

2013 ◽  
Vol 747-748 ◽  
pp. 690-696 ◽  
Author(s):  
Su Gui Tian ◽  
Y.C. Xue ◽  
Z. Zeng
Keyword(s):  
Creep Resistance ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Medium Temperature ◽  
Creep Properties ◽  
Nickel Based Superalloy ◽  
Microstructure Observation ◽  
Composition Segregation ◽  
Deformation Features ◽  
Different Temperatures

By means of solution treatment at various temperatures, creep properties measurement and microstructure observation, the effects of heat treatment on composition segregation and creep properties were investigated. Results show that the various segregation extents of the elements are displayed in the alloys solution treated at different temperatures, and the segregation extent of the elements is improved with the solution temperature elevated, which may obvious improve the creep resistance of the alloy. And no rafted structure of the γ phase is detected in the alloy during creep at medium temperature. The deformation features of the alloy during creep at medium temperature are that the slipping of dislocations is activated in the γ matrix channels, and dislocations shearing into the γ phase may be decomposed to form the configuration of partials + stacking faults, which may hinder the cross-slipping of the dislocations to improve the creep resistance of the alloy.

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