Influence of thermal exposure on microstructure and stress rupture property of a Re-containing Ni-based single crystal superalloy

2021 ◽  
Vol 136 ◽  
pp. 107237
Author(s):  
Xinxin Liu ◽  
Taiwen Huang ◽  
Jiachen Zhang ◽  
Dong Wang ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Stress Rupture ◽  
Thermal Exposure ◽  
Single Crystal Superalloy ◽  
Stress Rupture Property

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.

Effect of Minor Elements on the Grain Boundary Strengthening of a Single Crystal Superalloy RR2072

2007 ◽  
Vol 124-126 ◽  
pp. 1405-1408
Author(s):  
D.H. Kim ◽  
Y.S. Yoo ◽  
Chang Yong Jo ◽  
C.N. Jones
Keyword(s):  
Grain Boundary ◽  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Thermal Exposure ◽  
Single Crystal Superalloy ◽  
M23c6 Carbide ◽  
Carbide Formation ◽  
Minor Elements ◽  
Grain Boundary Strengthening

Effect of carbon and boron on the grain boundary strengthening of a second generation single crystal superalloy RR2072 was investigated. Single crystal and bicrystal specimen with three kinds of tilt type misorientation angle were grown by Bridgman technique. Creep and stress rupture tests were conducted at 950oC and 1050oC. Rupture life of single crystal of the alloy modified with carbon and boron was comparable to that of the RR2072 which is free from boron and carbon. TCP phase precipitation such as sigma was suppressed in the modified alloy during thermal exposure and creep deformation. Rupture life of the modified alloy bicrystal was superior to that of the RR2072 bicrystal. M23C6 carbide formation and suppression of γ′ band growth is thought to be the role of minor elements for the grain boundary strengthening of a nickel base single crystal superalloy RR2072.

Influence of Cooling Method on the Microstructure and Stress Rupture Property of a Single Crystal Superalloy

2015 ◽  
Vol 816 ◽  
pp. 513-517 ◽  
Author(s):  
Zhen Xue Shi ◽  
Shi Zhong Liu ◽  
Xiao Guang Wang ◽  
Jia Rong Li
Keyword(s):  
Single Crystal ◽  
Cooling Rate ◽  
Stress Rupture ◽  
Single Crystal Superalloy ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Rupture Property ◽  
Cooling Method ◽  
Stress Rupture Properties ◽  
Rupture Properties

The single crystal superalloy with [001] orientation were prepared by screw selecting method in the directionally solidified furnace. Three different cooling method, water cooling (WC), air cooling (AC) and furnace cooling (FC) were used after same solution treatment. Then these specimens received same two-step aging treatment. Influence of solution cooling method on the microstructure and stress rupture properties of the alloy under the test condition of 980 °C and 300 MPa was investigated. The microstructures of the samples were examined by scanning electron microscope (SEM). The results showed that the solution cooling method of heat treatment played an important role in the microstructure and stress rupture properties of the alloy. The size of γ′ phase and the width of the γ matrix channel of the alloy increased with decreasing cooling rate. The stress rupture properties of the alloy increased at first and decreased afterwards with decreasing cooling rate. The alloy with air cooling (AC) has the best stress rupture properties. The γ′ phase changed into a perfect raft structure during the stress rupture process of the specimens with AC method. However, the γ′ phase changed into a very irregular raft microstructure in the specimens with the water cooling (WC) and furnace cooling (FC) method. The micro-cracks in the specimen with irregular raft make the initiation and interconnection easier than that in the specimen with regular raft. Therefore, the alloy with AC method has optimum microstructure and stress rupture property.

New Phases in a Multicomponent High Ruthenium Single Crystal Superalloy

2005 ◽  
Vol 475-479 ◽  
pp. 655-660 ◽  
Author(s):  
Q. Feng ◽  
L.J. Rowland ◽  
T.M. Pollock
Keyword(s):  
Single Crystal ◽  
Dendritic Structure ◽  
Thermal Exposure ◽  
Single Crystal Superalloy ◽  
Heusler Phase ◽  
Topologically Close Packed ◽  
Tcp Phases ◽  
Δ Phase

Three unusual Ru-rich phases have been identified in a multicomponent Ni-base single crystal superalloy, including a L21 Ru2AlTa Heusler phase, a B2 RuAl phase and a hcp Re(Ru)-rich δ phase. These phases have their own preferential precipitation location within the dendritic structure. No conventional topologically-close-packed (TCP) phases have been observed with thermal exposure at 950oC for 1500 hours.

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