Effect of heat treatment on microstructure and stress rupture life of DD32 single crystal Ni-base superalloy

2007 ◽  
Vol 460-461 ◽  
pp. 420-427 ◽  
Author(s):  
Jinjiang Yu ◽  
Xiaofeng Sun ◽  
Nairen Zhao ◽  
Tao Jin ◽  
Hengrong Guan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Base Superalloy

Effect of Heat Treatment on Microstructure and Mechanical Properties for a Ni3Al Base Single Crystal Alloy DDIC6

2007 ◽  
Vol 546-549 ◽  
pp. 1443-1446 ◽  
Author(s):  
Zhi Gang Kong ◽  
Lei Ji ◽  
Shu Suo Li ◽  
Ya Fang Han ◽  
Hui Bin Xu
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Constant Load ◽  
Heat Treatment Condition ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Single Crystal Alloy ◽  
Proper Size

The effect of heat treatment on microstructures and stress rupture property of a Ni3Al base single crystal alloy DDIC6 was studied in the present investigate. The single crystal specimens were produced by screw selection crystal method. The heat treatment for the alloy was 1300°C/10h+1120°C/4h+870°C/32h and 1300°C/10h+870°C/32h.The microstructures were examined by SEM, TEM and X-ray EDS techniques. The stress rupture tests were carried out in air by constant load creep machines under 1100°C/130MPa with the specimens size of φ5×25 mm. The experimental results showed that the as-cast large size γ′ phases entirely dissolved after 1300°C/10h, and secondary fine γ′ phases precipitated by following aging at 1120°C and 870°C for certain periods of time. The stress rupture life under 1100°C/130MPa increased from 20~30hrs for as-cast condition to 60~100hrs for heat treatment condition. The improvement of the creep resistance of the alloy may attribute to the decrement of the elements segregation at dendrite and interdendritic areas, and the proper size and distribution of γ′ phases.

Microstructure Evolution and Stress Rupture Properties of DD6 Single Crystal Superalloy after Overheating

2017 ◽  
Vol 898 ◽  
pp. 517-522 ◽  
Author(s):  
Shi Zhong Liu ◽  
Zhen Xue Shi ◽  
M. Han ◽  
Jia Rong Li
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Standard Heat Treatment ◽  
Stress Rupture Life ◽  
Matrix Channel ◽  
Standard Heat ◽  
Stress Rupture Properties ◽  
Rupture Properties

The second generation single crystal superalloy DD6 after standard heat treatment was respectively overheated at 1100°C, 1150°C, 1200°C, 1250°C, 1300°C, 1320°C for 1h and air cooled. The effect of overheating on the microstructure and stress rupture properties at 980°C/250MPa of the alloy was investigated. The results showed that the size of γ′ phase was slightly increased overheating at 1100°C, 1150°C and 1200°C. The size of γ′ phase had a big increase and its size distribution was very uneven after overheating at 1250°C. The small part of γ′ phase has serrated γ′/γ phase surface as a result of un-completely solution and the irregular small γ′ phase was in the majority when overheated at 1300°C. While all the irregular small γ′ phase precipitated again after completely solution when overheated at 1320°C. There was no fine second γ′ phase in the γ matrix channel of the alloy after standard heat treatment and overheating at 1320°C. But the fine second γ′ phase precipitated in the γ matrix channel after overheating at every temperature of 1100 °C~1300°C. No obvious change of the stress rupture life was found after overheating at 1100°C, 1150°C, 1200°C and 1250°C. The stress rupture life considerably reduced after overheating at 1300°C, whereas slightly reduced after overheating at 1320°C. The appearance of the raft had almost no change after overheating at 1100°C. With increasing of overheating temperature from 1100°C to 1250°C, the length of raft became shorter and the width thickening. The γ phase formed the wavy raft after overheating at 1300°C and 1320°C and the thickness of latter was larger than that of the former. Finally, the relationship between the microstructural evolution and stress rupture properties of the alloy after overheating was discussed.

Mutation in TCP phases and superior stress rupture life led by W/Mo ratio in Ni-based single crystal superalloys

2022 ◽  
pp. 131656
Author(s):  
Jinbin Chen ◽  
Jingyang Chen ◽  
Qinjia Wang ◽  
Yidong Wu ◽  
Qing Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Tcp Phases

Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

2016 ◽  
Vol 849 ◽  
pp. 570-579
Author(s):  
Qiang Huang ◽  
Jin Xia Song ◽  
Qing Li ◽  
Wei Peng Ren ◽  
Xin Guang Guan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Room Temperature ◽  
Rupture Life ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.

Influence of Ageing Treatments on Stress Rupture Properties of Ni3Al-Base Single-Crystal Alloy IC21 at 850°C

2013 ◽  
Vol 747-748 ◽  
pp. 659-664 ◽  
Author(s):  
Hui Li ◽  
Fu Lin Li ◽  
Shu Suo Li ◽  
Heng Zhang ◽  
Sheng Kai Gong
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Heat Treatments ◽  
Air Cooling ◽  
Single Crystal Alloy ◽  
Stress Rupture Properties ◽  
Microstructure Examination ◽  
Rupture Properties

The influence of three different ageing treatments (R1:1100/2h,air cooling+870/32h,air cooling, R2: 870/32h,air cooling and R3: 1060/2h,air cooling+870/32h,air cooling) on stress rupture properties of Ni3Al-base single-crystal alloy IC21 was investigated. The results indicate that ageing heat treatments have obvious effects on stress rupture properties of IC21 at 850/500Mpa. After R3 ageing treatment, IC21 alloy presents the longest rupture life and the smallest ellipticity and elongation compared to those after the other two ageing treatments. Microstructure examination shows that the mean size of γ precipitate is about 0.44μm after R3 ageing heat treatment (1060/2h, ac + 870/32h, ac). Transmission electron microscope (TEM) study on the rupture samples illustrates that after R1 and R2 ageing heat treatments, the density of stacking faults increases and the length is larger compared to that after R3 heat treatment. Meanwhile the shearings of γ precipitates are more severe. The appropriate γ phase size and γ channel width after R3 treatment promote homogenous deformation by <110>{111} slip in the matrix, and facilitate the formation of finer dislocation networks on the γ/γ interface, which can restrain the shearing of γ phase by dislocations.

Role of Rhenium in Single Crystal Ni-Based Superalloys

2010 ◽  
Vol 638-642 ◽  
pp. 2257-2262 ◽  
Author(s):  
Tao Jin ◽  
Wen Zhen Wang ◽  
Xiao Feng Sun ◽  
Zhuang Qi Hu
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Solution Process ◽  
Stress Rupture ◽  
Nominal Composition ◽  
Stress Rupture Life ◽  
Dislocation Configuration ◽  
Rhenium Addition ◽  
Rhenium Content

The effect of rhenium on the microstructure and mechanical properties of single crystal superalloys with a nominal composition of Ni-3Cr-12Co-1Mo-6W-6Al-8Ta-0.1Hf-(0, 2, 4) Re has been studied. With the rise of rhenium content, the size of as-cast  particles becomes smaller. Rhenium addition elevates the incipient melting temperature and slows down the solid solution process. Even after 2000h prolonged aging both at 950°C and 1050°C, no topologically close-packed phase precipitation is found in the three alloys with Re content up to 4%. Re retards the  coarsening and is beneficial to improving the stress rupture life. The deformation mechanisms together with the dislocation configuration have been studied and discussed.

Influence of Heat Treatment on γ´ Phase and Property of a Directionally Solidified Superalloy

2018 ◽  
Vol 37 (3) ◽  
pp. 271-276
Author(s):  
P. C. Xia ◽  
K. Xie ◽  
H. Z. Cui ◽  
J. J. Yu
Keyword(s):  
Heat Treatment ◽  
Aging Temperature ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
Nickel Base Superalloy ◽  
Directionally Solidified ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Nickel Base

AbstractThe effects of heat treatment process on microstructure and properties of a nickel base superalloy are investigated. The size of γ´ phase decreases and the stress rupture life of alloy at 1100 °C/60 MPa drops with the rise of cooling rate. The hardness at room temperature also increases. The size of cuboidal γ´ precipitate and the volume of spherical γ´ precipitate increase with the rise of aging temperature. With higher aging temperature, the alloy exhibits bimodal γ´ phase. A reasonable combination of the size and volume fraction of cuboidal and spherical γ´ phase can obtain better stress rupture property at 1100 °C/60 MPa.

EFFECTS OF CRYSTAL ORIENTATION ON STRESS RUPTURE BEHAVIOR OF A Ni3Al-BASE SINGLE CRYSTAL SUPERALLOY IC6SX

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2952-2957
Author(s):  
LIWU JIANG ◽  
SHUSUO LI ◽  
MEILING WU ◽  
YAFANG HAN
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Crystal Orientation ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Area Reduction ◽  
Crystal Orientations ◽  
Rupture Behavior

The effect of the crystal orientation on the stress rupture behavior of the Ni 3 Al -base Single Crystal alloy IC6SX under the test condition of 1100°C/120Mpa has been studied. The results showed that the stress rupture lives of the specimens with [001], [011] and [111] crystal orientations were 205.45h, 268.6h and 485h, respectively, i.e., the specimen with [111] crystal orientation had the longest stress rupture life. The results of the tests also showed the significant different of high temperature stress rupture elongation and area reduction for different crystal orientation specimens, i.e., the ruptured elongations for the specimens with [001], [011] and [111] crystal orientations were 61.9%, 22.9% and 28.8%, and the values of area reduction for the specimens with [001], [011]and [111] crystal orientations were 11.7%, 12.2%and 7.3% respectively.

Mechanical Behavior of As-Cast and High Temperature Exposed Ni-Base Superalloy B1900

2004 ◽  
Vol 449-452 ◽  
pp. 541-544 ◽  
Author(s):  
I.S. Kim ◽  
Baig Gyu Choi ◽  
Seong Moon Seo ◽  
Chang Yong Jo
Keyword(s):  
High Temperature ◽  
Tensile Deformation ◽  
Rupture Life ◽  
Stress Rupture ◽  
Thermal Exposure ◽  
Tensile Specimen ◽  
Dislocation Network ◽  
Stress Rupture Life ◽  
Cast Specimen ◽  
Base Superalloy

Microstructural evolution during high temperature exposure and its effects on tensile and stress rupture properties of the Ni-base superalloy B1900 have been studied. Tensile deformation of the as-cast specimen was concentrated in the localized slip bands in general. Stacking faults and deformation twins were observed in the as-cast tensile specimen tested at 871°C where the alloy exhibited the lowest ductility. Dense dislocation network formed at γ/γ´ interface during thermal exposure caused homogenous deformation in the thermally exposed tensile specimen. Thermal exposure did not have significant effect on the stress rupture lives of the alloy at 760°C and at and above 871°C but it reduced stress rupture life of the alloy at 816°C γ´ coarsening and coherency loss at the γ/γ´ interface during thermal exposure were primarily responsible for the deterioration of mechanical properties and characteristic deformation behavior of the alloy.

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