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.

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

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.

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.

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.

Effect of Low-Angle Boundary on Microstructure and Stress Rupture Property of a Third Generation Single Crystal Superalloy DD10

2017 ◽  
Vol 898 ◽  
pp. 498-504
Author(s):  
Hui Fen Li ◽  
Li Jun Liu ◽  
Ming Xue ◽  
La Mei Cao
Keyword(s):  
Grain Boundary ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Chain Structure ◽  
Single Crystal Superalloy ◽  
Third Generation ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Remarkable Effect

The microstructure of a third generation single crystal superalloy DD10 with 0°~15° grain boundary and stress rupture property at 980°C/280MPa and 1100°C/140MPa have been studied and compared in the present investigation. The results showed that the primary dendritic stems at either side of low angle boundary indicated angular differences as compared with structure of principal [001] crystal. After thermal treatment, the grain boundary changed from irregular chain structure of γ’ and γ to flat and thin γ layer. Under the condition of 980°C/280MPaand 1100°C/140MPa, stress rupture life of the DD10 alloy with 7° low angle boundary decreased little compared with [001] crystal. The rupture was non-intergranular fracture. The 9° low angle boundary did not have a remarkable effect on stress rupture property of the DD10 alloy.

Influence of Withdrawal Rate on Tensile and Stress Rupture Properties of the Single Crystal Superalloy DD9

2013 ◽  
Vol 747-748 ◽  
pp. 625-628 ◽  
Author(s):  
Z.X. Shi ◽  
J.R. Li ◽  
Shi Zhong Liu
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Single Crystal Superalloy ◽  
Withdrawal Rate ◽  
Stress Rupture Life ◽  
The Third ◽  
Stress Orientation ◽  
Stress Rupture Properties ◽  
Rupture Properties

The third generation single crystal superalloy DD9 was processed with different withdrawal rates and the effect of withdrawal rate on the tensile and stress rupture properties of the alloy was investigated. The relation between the mechanical properties and microstructure of the alloy with different withdrawal rates was discussed. The results showed that the withdrawal rate had a little effect on the tensile properties at 25 of the alloy. The tensile strength at 980 and stress rupture life at 1120/140MPa of DD9 alloy all increased with the increasing of withdrawal rate. The γ precipitates of specimen tensile at 25 had a little extension in the stress orientation. The extension of γ precipitates in the stress orientation at 980 was much more than that at 25. The vertical γ matrix at 980 became thinner and horizontal γ matrix became thicker slightly. The γ precipitates of those had rafted in a direction transverse to the applied stress.

scholarly journals Influence of Phosphorus Addition on the Stress Rupture Properties of Direct Aged IN706 Superalloy

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 641
Author(s):  
Sha Zhang ◽  
Anwen Zhang ◽  
Chaochao Xue ◽  
Dan Jia ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Rupture Life ◽  
Stress Rupture ◽  
Phosphorus Addition ◽  
Stress Rupture Life ◽  
P Concentration ◽  
Stress Rupture Properties ◽  
Rupture Properties ◽  
The Relationship ◽  
P Addition

This study investigated the influence of phosphorus (P) addition on the stress rupture properties of direct aged IN706 superalloy. The results showed that P slightly improved the stress rupture life of the superalloy when added in the range between 0.002% and 0.008%; however, it significantly reduced the stress rupture life when added in the range between 0.013% and 0.017%. Microstructure characterization indicated that the precipitation of γ′, γ″, and η phases was not significantly affected by the addition of P. Phosphides precipitated in the alloy containing 0.017% P after aging at 980 °C for 10 min. Compared to a similar study previously made on IN706 superalloy, it was found that the optimum P concentration in the as-solutioned state for improving the stress rupture properties was not definite. Furthermore, the relationship between the amount of P segregated at the grain boundary and the role of P on the stress rupture properties was discussed.

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.

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