文献类型：期刊文献

英文题名：Mechanistic investigation of pre-exposure-induced interfacial degradation and crack initiation behavior in MCrAlY-coated DD91 superalloy

作者：Liu, Pengpeng[1];Wang, Kangkang[1,2];Liu, Yangguang[1,3];Wang, Weize[1,4];Tan, Jianping[1,4];Zhang, Xiaoqin[1];Zhang, Wenkang[1];Li, Hongchen[1];Wang, Junhao[1];Li, Kaibin[1];Tu, Shantung[1,4]

机构：[1]East China Univ Sci & Technol, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]City Univ Hong Kong, Dept Mech Engn, Kowloon, 83 Tat Chee Ave, Hong Kong, Peoples R China;[3]Zhejiang Acad Special Equipment Sci, Zhejiang Key Lab Special Equipment Safety Technol, Hangzhou 310000, Peoples R China;[4]Shanghai Inst Aircraft Mech & Control, Shanghai 200092, Peoples R China

年份：2026

卷号：340

外文期刊名：ENGINEERING FRACTURE MECHANICS

收录：;EI(收录号：20261620540786);WOS:【SCI-EXPANDED(收录号:WOS:001752084400001)】；

基金：This research was funded by the Science Center for Gas Turbine Project, China (P2021-A-IV-002-002) , National Natural Science Foundation of China, China (52175136, 52130511) , Shanghai Gaofeng Project for University Academic Program Development, China, Civil Space 'the 14th Five-Year Plan' Pre-research Project, China (D050101) , National High Technology Research and Development Program of China, China (2023YFB3711200) .

语种：英文

外文关键词：MCrAlY; Fourth-generation Ni-based single-crystal superalloy; Low-cycle fatigue; Pre-exposure; Microstructural analysis

摘要：MCrAlY coatings are widely applied to protect hot-section components, yet deposition and subsequent pre-exposure treatment can alter the coating/substrate interface and degrade fatigue performance. This study evaluates the low-cycle fatigue (LCF) response of an atmospheric plasma-sprayed deposited MCrAlY coating on a fourth-generation Ni-based single-crystal superalloy (DD91) at 900 degrees C, using a newly designed tandem specimen concept, which is intended to enable simultaneous quantification of fatigue life and subcritical damage in a single test. Three conditions were examined: bare (uncoated), as-sprayed (coated without pre-exposure), and pre-exposure (1150 degrees C/100 h). Relative to the bare substrate, the as-sprayed coating exhibited a substantially longer LCF life, whereas pre-exposure reduced fatigue life compared with the as-sprayed state and shifted crack initiation from subsurface casting defects to the near-surface coating/recrystallized layer (RL) region. Electron backscatter diffraction revealed a similar to 40 mu m RL at the coating/substrate interface following pre-exposure. Finite-element analysis, interpreted via an equivalent strain-energy-density metric, showed that this layer steepened the near-surface stress gradient, which may contribute to the observed transition toward crack initiation in the near-surface coating/RL region. These results suggest that, within the specific loading configuration investigated, pre-exposure-induced interfacial degradation is closely associated with the transition to premature fatigue failure.