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.

Influence of Withdrawing Rates on Elements Segregation and Creep Properties of A Single Crystal Nickel-Based Superalloy

2012 ◽  
Vol 31 (2) ◽  
Author(s):  
Sugui Tian ◽  
Chao Zhang ◽  
Xingfu Yu ◽  
Zheng Zeng ◽  
Yong Su
Keyword(s):  
Single Crystal ◽  
Creep Resistance ◽  
Creep Property ◽  
Dendrite Spacing ◽  
Creep Properties ◽  
Nickel Based Superalloy ◽  
Microstructure Observation ◽  
Observation Results

AbstractThe single crystal nickel-based superalloys with different dendrite spacings were prepared by using various withdrawing rates, and the influence of withdrawing rates on elements segregation and creep properties of them is investigated through creep property measurements and microstructure observation. Results show that relatively bigger withdrawing rate leads to the smaller dendrite spacing and lower segregation extent of elements between the dendrite/interdendrite regions, which further causes the better creep resistance of the alloy. Dislocations climbing over the rafted

Microstructure and Tensile Deformation Features of Tandem Hot Rolling GH4169 Superalloy

2014 ◽  
Vol 33 (2) ◽  
pp. 131-136
Author(s):  
Zhenrong Li ◽  
Chunlei Ma ◽  
Sugui Tian ◽  
Liqing Chen ◽  
Xianghua Liu
Keyword(s):  
Hot Rolling ◽  
Tensile Deformation ◽  
Solution Treatment ◽  
Microstructure Observation ◽  
Large Numbers ◽  
Initiation And Propagation ◽  
The Matrix ◽  
Deformation Features ◽  
Δ Phase ◽  
Property Measurement

AbstractBy means of solution treatment, microstructure observation and mechanical property measurement, the microstructure and tensile deformation features of tandem hot rolling GH4169 alloy have been investigated. Results shown that, after solution treatment and aging, large numbers of the spherical γ′ phase and the flat-ellipsoidal γ″ phase dispersedly precipitate in the matrix, and acicular or short rod-like δ-phase discontinuously distribute along grain boundaries. As the tensile temperatures increases, the tensile strength and yield strength of the alloy gradually decrease. The tensile deformation features of the alloy are that the twinning and slipping dislocations with double orientations are activated in the matrix. In the later tension, the deformed dislocations pile up near the grain boundary to induce initiation and propagation of cracks due to stress concentration.

Effect of High-Pressure Solution Temperature on Corrosion Resistance of AM60 Magnesium Alloy

2012 ◽  
Vol 580 ◽  
pp. 560-563
Author(s):  
Guang Hui Chen
Keyword(s):  
High Pressure ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Pressure Solution ◽  
Different Temperatures ◽  
Increasing Temperature

As-cast AM60 magnesium alloy was solid dissolved under a high-pressure of 4 Gpa at different temperatures. The microstructure of the products was observed by optical microscope and the corrosion resistance of the products was investigated. The results show that increasing temperature during solution treatment promotes the dissolution into α-Mg matrix of β-Mg17Al12 in the alloy and improves the corrosion resistance of AM60 alloy, especially for over 400 °C.

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.

Effect of Solution Treatment on Corrosion Resistance of the Biodegradable NZ20K Alloy

2016 ◽  
Vol 849 ◽  
pp. 196-202
Author(s):  
Yang Fei ◽  
Xiao Bo Zhang ◽  
Zhi Xin Ba ◽  
Zhang Zhong Wang
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Corrosion Rate ◽  
Scanning Electron Microscope ◽  
Biomedical Applications ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Solution Treated ◽  
Different Temperatures ◽  
Scanning Electron

In order to study the effect of solution temperature on corrosion resistance of Mg alloy for biomedical applications, microstructure and corrosion behavior of Mg-2.25Nd-0.11Zn-0.43Zr (NZ20K) alloy solution treated at different temperatures were investigated by using a scanning electron microscope (SEM) equipped with an electron dispersive spectroscope (EDS), electrochemical and mass loss tests. The results show that the grains grow and precipitations decreases with increasing the solution temperature. The corrosion rate decreases firstly and then increases with increasing solution temperature, and the best corrosion resistance of the NZ20K alloy is obtained at the temperature of 540 °C.

Influences of Solution Treatment, Deformation Strain and Nanometric Al2O3 Particulate on Hardness for Nanometric Al2O3 Particulate Reinforced Al Alloy Matrix Composites Manufactured by Casting

2012 ◽  
Vol 430-432 ◽  
pp. 88-91
Author(s):  
Yong Biao Yang ◽  
Zhi Min Zhang ◽  
Mu Meng
Keyword(s):  
Solution Treatment ◽  
Solution Temperature ◽  
Al Alloy ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Deformation Strain ◽  
Microstructure Observation ◽  
Deformation And Heat Treatment ◽  
Particulate Reinforced ◽  
Al Matrix

The influences of solution treatment, deformation strain, and nanometric Al2O3 particulate on hardness for nanometric Al2O3 particulate reinforced Al alloy matrix Composites manufactured by casting were investigated. The result showed that both the hardness of AL matrix and the hardness of the composites increased dramatically with increasing solution temperatures. The hardness increased slightly with increasing deformation strain for the composites. The hardness of the composites is higher than the AL matrix after the same deformation and heat treatment. Microstructure observation revealed that the grain sizes of the composites increased with increasing solution temperature and decreased with more severe deformation.

scholarly journals Effect of silicon on creep properties of titanium 6Al-2Sn-4Zr-2Mo alloy

2020 ◽  
Vol 321 ◽  
pp. 04021
Author(s):  
M-L Anti ◽  
V Collado Ciprés ◽  
J Mouzon ◽  
P. Åkerfeldt ◽  
R Pederson
Keyword(s):  
Creep Resistance ◽  
Elevated Temperatures ◽  
Beta Phase ◽  
Optical Microscope ◽  
Creep Tests ◽  
Creep Properties ◽  
Aerospace Applications ◽  
Different Temperatures ◽  
Light Optical Microscope ◽  
Scanning Electron

The alloy Ti-6Al-2Sn-4Zr-2Mo is a titanium alloy for elevated temperatures often used in aerospace applications. Minor additions of silicon have proven to improve the creep resistance of this alloy. In this work, three different amounts of silicon (0.015, 0.07 and 0.162 wt% Si) were added to cast Ti-6242 and creep tests were performed at different temperatures and loads. Creep resistance increased significantly with silicon addition by means of silicide precipitation hindering dislocations movement. Silicon rich nanoparticles in the microstructure were detected and their effect on creep resistance was investigated. The instruments used in this study were light optical microscope (LOM) and scanning electron microscopy (SEM). Precipitates larger than 150 nm were found to be located heterogeneously in the microstructure, whereas smaller precipitates, ranging from 20-100 nm were homogeneously spread in the material. All silicides were predominantly situated next to the beta-phase in the alloy, either at the prior-beta grain boundaries or the beta-phase in between the alpha-colonies.

Influence of Element Re on Creep Behavior of Single Crystal Nickel-Based Superalloys at Intermediate Temperature

2013 ◽  
Vol 32 (1) ◽  
pp. 7-13
Author(s):  
Sugui Tian ◽  
Xianlin Meng ◽  
Zeng Zeng ◽  
Chao Zhang ◽  
Chen Liu
Keyword(s):  
Single Crystal ◽  
Creep Resistance ◽  
Rupture Life ◽  
Intermediate Temperature ◽  
Stress Axis ◽  
Nickel Base Superalloy ◽  
Microstructure Observation ◽  
Heat Treated ◽  
Deformation Features ◽  
Nickel Base

AbstractBy means of creep curves measurement and microstructure observation, an investigation has been made into the influence of the element Re on creep behaviors of single crystal nickel-base superalloy at intermediate temperature. Results show that, after fully heat treated, microstructure of the alloy consists of the cubic γ′ phase embedded coherent in the γ matrix. Comparing with Re-free superalloy, 4.5% Re alloy displays a better creep resistance and longer creep rupture life in the ranges of the applied stresses and temperatures. After crept for 425 h up to fracture at 760 °C/800 MPa, the γ′ phase in the alloy keeps still the regular cubical configuration, which is attributed to the effect of the element Re decreasing the diffusing rate of other elements during creep. The deformation features of the alloy during creep are that the dislocations move in the γ matrix channels and shear into the γ′ phase, the 〈110〉 super-dislocation shearing into the γ′ phase may be decomposed to form the configuration of (1/3)〈112〉 super-Shockleys partials plus the stacking fault, which may hinder dislocations movement and restrain the cross-slipping of dislocations. This is thought to be the main reason of the alloy having a better creep resistance. In the latter stage of creep, the crack is firstly initiated in the interface of γ′/γ phases and propagated along the interface vertical to the stress axis up to the occurrence of the creep fracture, which is thought to be the fracture mechanism of the alloy during creep.

Effect of Element Re on Creep Behaviour of a Single Crystal Nickel-Based Superalloy

2011 ◽  
Vol 194-196 ◽  
pp. 1265-1269
Author(s):  
Hui Liu ◽  
Ming Gang Wang ◽  
Su Gui Tian
Keyword(s):  
Single Crystal ◽  
Creep Resistance ◽  
Creep Behaviour ◽  
Primary Creep ◽  
Steady State Creep ◽  
Nickel Based Superalloy ◽  
Microstructure Observation ◽  
Lower Strain ◽  
Dislocation Reaction ◽  
The Matrix

By means of measuring creep curves and microstructure observation, the influence of the element Re on creep behaviour of the single crystal superalloy has been investigated. Results shown that the creep resistance of nickel-based superalloy with element Re may be obviously improved and the 2% Re superalloy had lower strain rate and longer creep lifetimes compared with Re-free single crystal alloy. The activation energy and stress exponent of the 2% Re superalloy during steady state creep were measured to be Q =478.6 kJ/mol and n = 5.1 respectively. The deformed features of the 2% Re alloy during primary creep are dislocation slipping in the matrix channels, dislocation networks are formed by dislocation reaction, and creep resistance may be improved when networks on the γ/γ’ phases interfaces. In the tertiary creep stage, deformation mechanism is the <110> super-dislocation shearing into the rafted γ’ phase.

scholarly journals Influence of Forging and Heat Treatment on the Microstructure and Mechanical Properties of a Heavily Alloyed Ingot-Metallurgy Nickel-Based Superalloy

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1606
Author(s):  
Valery Imayev ◽  
Shamil Mukhtarov ◽  
Kamilla Mukhtarova ◽  
Artem Ganeev ◽  
Ruslan Shakhov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Creep Resistance ◽  
Solution Treatment ◽  
Ingot Metallurgy ◽  
Fine Grained ◽  
Nickel Based Superalloy ◽  
Solid Solution Treatment ◽  
Interphase Boundaries ◽  
Microstructure Examination

The newly designed ingot-metallurgy nickel-based superalloy SDZhS-15 intended for disc applications at operating temperatures up to 800–850 °C was subjected to homogenization annealing and canned forging at subsolvus temperatures, followed by solid solution treatment and ageing. Mostly a fine-grained recrystallized microstructure was obtained in the forgings. It was revealed that post-forging solid solution treatment at T > (Ts-50), where Ts is the γ′ solvus temperature, led to a significant γ grain growth, which in turn led to a decrease in strength and ductility of the superalloy. The solution treatment at (Ts-60)–(Ts-50) allowed to save fine γ grains (dγ = 10–20 μm) and to provide the formation of secondary γ′ precipitates with a size of around 0.1 μm. In the forged and heat-treated conditions, the superalloy demonstrated superior mechanical properties, particularly excellent creep resistance at 650–850 °C in the stress range of 400–1200 MPa. Microstructure examination of the creep-tested samples showed that a decrease in the creep resistance at 850 °C can be associated with enhanced diffusivity along γ grain and γ/γ′ interphase boundaries leading to formation of cracks along the boundaries. In spite of the heavy alloying, the topologically close-packed phases were not detected in the superalloy, including in the creep tested samples.

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