Thermal-Stress Coupling Effect on Microstructure Evolution of a Fourth-Generation Nickel-Based Single-Crystal Superalloy at 1100 degrees C

doi:10.11900/0412.1961.2020.00216

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	Thermal-Stress Coupling Effect on Microstructure Evolution of a Fourth-Generation Nickel-Based Single-Crystal Superalloy at 1100 degrees C
	Xu Jinghui 2; Li Longfei 2; Liu Xingang 1; Li Hui 1; Feng Qiang 2
刊名	ACTA METALLURGICA SINICA
	2021-02-11
卷号	57 期号:2 页码:205-214
关键词	forth-generation nickel-based single-crystal superalloy high temperature and low stress variable cross-section creep microstructure evolution gamma ' phase
ISSN号	0412-1961
DOI	10.11900/0412.1961.2020.00216
通讯作者	Li Longfei(lilf@skl.ustb.edu.cn)
英文摘要	The mechanism of microstructure evolution and its effect on the mechanical properties of nickel-based single-crystal superalloys during creep at high temperatures and low stresses are critical to the development of advanced single-crystal superalloys for aeroengines with high thrust: weight ratios. In this work, the microstructural evolution of a fourth-generation nickel-based single-crystal superalloy during creep at 1100 degrees C for 200 h at various stress levels was investigated using a specially designed sample with variable cross-sections, with the aim of obtaining different applied stresses synchronously on a single sample. The effects of applied stress on gamma/gamma' microstructure, interfacial dislocation configuration, alloy element partitioning behavior, and lattice misfit of gamma/gamma' phases of the used single-crystal superalloy were also studied, as were the effects on room temperature Vickers hardness. The results indicated that the typical rafting microstructure was formed during creep over the 200 h period at 1100 degrees C under various stress levels. With increasing applied stress, the volume fraction and rafted thickness of the gamma' phase gradually decreased, while the rafting degree of the gamma' phase and the channel width of the gamma phase gradually increased. A dense interfacial dislocation network was formed at the gamma/gamma' interface, and interfacial dislocation spacing decreased with increasing applied stress. Simultaneously, increased partitioning of solution-strengthening elements Re, Mo, and Cr to the gamma phase and increased partitioning of gamma'-strengthening element Ta to the gamma' phase resulted in a larger absolute value of gamma/gamma' lattice misfit at higher stress. In addition to the decreases in volume fraction and rafted thickness of the gamma' phase and the increase in channel width of the gamma phase, another important factor in the strength decline of the single-crystal superalloy was the pile-up of dislocations at bent gamma/gamma' interface boundaries, mainly caused by the dissolution of the gamma' phase and promotion of dislocation shear into the gamma' phase. This work provides a basis for quickly establishing the relationship between creep conditions and microstructure evolution of nickel-based single-crystal superalloys.
资助项目	National Key Research and Development Program of China[2016YFB0701403] ; National Science and Technology Major Project
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000613192500006
资助机构	National Key Research and Development Program of China ; National Science and Technology Major Project
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/160910]
专题	金属研究所_中国科学院金属研究所
通讯作者	Li Longfei
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 2.Univ Sci & Technol Beijing, Beijing Innovat Ctr Mat Genome Engn, State Key Lab Adv Met & Mat, Beijing 100083, Peoples R China
推荐引用方式 GB/T 7714	Xu Jinghui,Li Longfei,Liu Xingang,et al. Thermal-Stress Coupling Effect on Microstructure Evolution of a Fourth-Generation Nickel-Based Single-Crystal Superalloy at 1100 degrees C[J]. ACTA METALLURGICA SINICA,2021,57(2):205-214.
APA	Xu Jinghui,Li Longfei,Liu Xingang,Li Hui,&Feng Qiang.(2021).Thermal-Stress Coupling Effect on Microstructure Evolution of a Fourth-Generation Nickel-Based Single-Crystal Superalloy at 1100 degrees C.ACTA METALLURGICA SINICA,57(2),205-214.
MLA	Xu Jinghui,et al."Thermal-Stress Coupling Effect on Microstructure Evolution of a Fourth-Generation Nickel-Based Single-Crystal Superalloy at 1100 degrees C".ACTA METALLURGICA SINICA 57.2(2021):205-214.