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.

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.

Stress Rupture Properties of the Second Generation Single Crystal Superalloy DD6 after High Temperature Exposure

2007 ◽  
Vol 546-549 ◽  
pp. 1249-1252 ◽  
Author(s):  
Hai Peng Jin ◽  
Jia Rong Li ◽  
Shi Zhong Liu
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Second Generation ◽  
Rupture Life ◽  
Stress Rupture ◽  
Single Crystal Superalloy ◽  
Stress Rupture Life ◽  
Stress Rupture Properties ◽  
Temperature Exposure ◽  
Rupture Properties

The effects of high temperature exposure simulating service conditions on stress rupture properties were studied for the second generation single crystal superalloy DD6. The specimens with [001] orientation were exposed in air at temperatures of 980°C and 1070°C for 100h to 1000h. They were then tested using conventional mechanical tests at 1070°C/140MPa to determine the effects of exposure on stress rupture properties. The analysis indicated that stress rupture life decreased with increasing exposure time. At the temperature of 980°C, the stress rupture life is more than 180h after exposure for 1000h. When the test temperature increased to 1070°C, the stress rupture life exceeds 100h after 800h exposure. The morphology of γ prime phase after exposure was observed by using scanning electron microscopy (SEM). Morphologies evaluations have shown that alloy DD6 exhibits excellent microstructure stability after exposure. TCP (Topologically Closed Packed) phases have not been observed. It has been also found that the morphology and size of γ prime affected stress rupture life of the alloy. The decrement in stress rupture life with increasing exposure is a result of γ prime rafting.

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

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

High-Temperature, Cobalt-Tungsten Alloys for Aerospace Applications

1965 ◽  
Vol 87 (1) ◽  
pp. 9-20 ◽  
Author(s):  
J. C. Freche ◽  
R. L. Ashbrook ◽  
G. D. Sandrock
Keyword(s):  
High Temperature ◽  
Rupture Strength ◽  
Rupture Life ◽  
High Stress ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Tungsten Alloys ◽  
Aerospace Applications ◽  
Temperature Capability ◽  
Nickel Base

The high-temperature capability and workability of cobalt-tungsten alloys for aerospace applications is discussed. The average life at 1850 F and 15,000 psi of the strongest previously reported alloy, Co-25 W-1Ti-1Zr-0.4C, was doubled from 92 to 185 hr by small additions of chromium and rhenium. At 2200 F and 5000 psi, the strongest alloy, Co-25W-1Ti-1Zr-3Cr-2Re-0.4C, had a rupture life of 23 hr; the elevated-temperature rupture strength compared favorably with the strongest available conventional (high-chromium) cobalt-base alloys. Above approximately 2035 F and at reasonably high stress levels (10,000 and 15,000 psi), its stress-rupture life also exceeded those of the strongest known nickel-base alloys, including the NASA tantalum-modified alloy and SM-200. It is particularly significant that even the strongest alloys of this series were readily hot-rolled. Ingots 1/2 in. thick were reduced to 0.065-in. sheet and subsequently cold-rolled to 0.0125-in. sheet. Elongations as high as 31 percent were obtained at room temperature with annealed sheet specimens. The good ductility obtained suggests that these alloys could be fabricated into complex shapes required for various aerospace and other applications. Although the strongest alloys had a chromium content of only 3 percent, they did not oxidize catastrophically in air.

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.

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.

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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