Research Progress in Nickel Base Single Crystal Superalloys

Nickel base single crystal superalloy is widely used in hot end parts of aeroengine because of its excellent creep, fatigue and oxidation resistance. In the face of strong market demand and the emergence of new technologies and methods, in 2019, nickel-based single crystal superalloys have made remarkable achievements in preparation and heat treatment processes, repair techniques, test methods, characterization methods, theoretical simulation analysis and composition design, which continuously promotes the development of nickel base single crystal superalloy to the direction of high performance and low cost. The present work reviews the progresses from preparation and heat treatment process, repair technology of service alloy structure, service evaluation of alloy, high flux composition design. The progress in the design, preparation and engineering application of superalloy materials will eventually promote the development of a new generation of aeroengine.

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Creep Behavior of a 4.5% Re Nickel-Base Single Crystal Superalloy at High Temperature

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.750.139 ◽

2015 ◽

Vol 750 ◽

pp. 139-144 ◽

Cited By ~ 1

Author(s):

De Long Shu ◽

Su Gui Tian ◽

Xin Ding ◽

Jing Wu ◽

Qiu Yang Li ◽

...

Keyword(s):

Heat Treatment ◽

High Temperature ◽

Single Crystal ◽

Deformation Mechanism ◽

Creep Property ◽

Single Crystal Superalloy ◽

Micro Cracks ◽

Initiation And Propagation ◽

Temperature Ranges ◽

Nickel Base

By means of heat treatment and creep property measurement, an investigation has made into the creep behaviors of a containing 4.5% Re nickel-base single crystal superalloy at high temperature. Results show that the elements W, Mo and Re are enriched in the dendrite arm regions, the elements Al, Ta, Cr and Co are enriched in the inter-dendrite region, and the segregation extent of the elements may be obviously reduced by means of heat treatment at high temperature. In the temperature ranges of 1070--1100 °C, the 4.5% Re single crystal nickel-based superallloy displays a better creep resistance and longer creep life. The deformation mechanism of the alloy during steady state creep is dislocations slipping in the γ matrix and climbing over the rafted γ′ phase. In the later stage of creep, the deformation mechanism of alloy is dislocations slipping in the γ matrix, and shearing into the rafted γ′ phase, which may promote the initiation and propagation of the micro-cracks at the interfaces of γ/γ′ phases up to the occurrence of creep fracture.

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Improvement of Creep strength in a nickel-base single-crystal superalloy by heat treatment

Materials Science and Engineering ◽

10.1016/0025-5416(83)90199-4 ◽

1983 ◽

Vol 61 (2) ◽

pp. 173-184 ◽

Cited By ~ 278

Author(s):

P. Caron ◽

T. Khan

Keyword(s):

Heat Treatment ◽

Single Crystal ◽

Creep Strength ◽

Single Crystal Superalloy ◽

Nickel Base

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Abnormal Increase of TCP Phase During Heat Treatment in a Ni-Based Single Crystal Superalloy

SSRN Electronic Journal ◽

10.2139/ssrn.3399182 ◽

2019 ◽

Author(s):

B. Yin ◽

G. Xie ◽

L.H. Lou ◽

J. Zhang

Keyword(s):

Heat Treatment ◽

Single Crystal ◽

Single Crystal Superalloy ◽

Abnormal Increase ◽

Tcp Phase

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The Effect of Tensile Stress on Oxidation Behavior of Nickel-Base Single Crystal Superalloy

Corrosion Science ◽

10.1016/j.corsci.2021.109737 ◽

2021 ◽

pp. 109737

Author(s):

Hai-Qing Pei ◽

Meng Li ◽

Ping Wang ◽

Xiao-Hu Yao ◽

Zhi-Xun Wen ◽

...

Keyword(s):

Tensile Stress ◽

Single Crystal ◽

Oxidation Behavior ◽

Single Crystal Superalloy ◽

Nickel Base

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Creep Damage Repair of a Nickel-Based Single Crystal Superalloy Based on Heat Treatment

Metals ◽

10.3390/met11040623 ◽

2021 ◽

Vol 11 (4) ◽

pp. 623

Author(s):

Xiaoyan Wang ◽

Meng Li ◽

Yuansheng Wang ◽

Chengjiang Zhang ◽

Zhixun Wen

Keyword(s):

Heat Treatment ◽

Single Crystal ◽

Creep Damage ◽

Primary Creep ◽

Single Crystal Superalloy ◽

Secondary Creep ◽

Creep Life ◽

Phase Coarsening ◽

Damage Repair ◽

Creep Time

Taking nickel-based single crystal superalloy DD6 as the research object, different degrees of creep damage were prefabricated by creep interruption tests, and then the creep damage was repaired by the restoration heat treatment system of solid solution heat treatment and two-stage aging heat treatment. The results show that with the creep time increasing, the alloy underwent microstructure evolution including γ′ phase coarsening, N-type rafting and de-rafting. After the restoration heat treatment, the coarse rafted γ′ phase of creep damaged specimens dissolved, precipitated, grew up, and became cubic again. Except for the specimens with creep interruption of 100 h, the γ′ phase can basically achieve the same arrangement as the γ′ phase of the original sample. The comparison of the secondary creep test shows that the steady-state creep stage of the test piece after the restoration heat treatment is relatively increased, and the total creep life can reach the same level as the primary creep life. The high temperature creep properties of the tested alloy are basically recovered, and the restoration heat treatment effect is good.

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