Effect of porosity and eutectics on the high-temperature low-cycle fatigue performance of a nickel-base single-crystal superalloy

SCRIPTA MATERIALIA

卷:155

Article

Ruttert, Benjamin¹  Meid, Carla²  Mujica Roncery, Lais^1,3,4  Lopez-Galilea, Inmaculada¹  Bartsch, Marion²  Theisen, Werner¹ 

[1] Ruhr Univ Bochum, Inst Werkstoffe, Lehrstuhl Werkstofftech, Bochum, Germany

[2] Deutsch Zentrum Luft & Raumfahrt, Inst Werkstoff Forsch, Cologne, Germany

[3] Univ Pedag & Tecnol Colombia, Grp Invest Mat Siderurg, Boyaca, Colombia

[4] Univ Pedag & Tecnol Colombia, INCITEMA, Boyaca, Colombia

关键词: Electron backscatter diffraction (EBSD);    Hot isostatic pressing (HIP);    Low-cycle fatigue;    Microstructure;    Single-crystal superalloy;   

DOI  :  10.1016/j.scriptamat.2018.06.036

来源: Elsevier

【 摘 要 】

This work investigates the separate influence of porosity and gamma/gamma'-eutectics on the low-cycle fatigue life of a single-crystal Ni-base superalloy at high temperatures. A conventional vacuum furnace heat-treatment but also integrated heat-treatments in a hot isostatic press are applied to produce different material variants of the same alloy. High-resolution electron microscopy revealed that both pores and gamma/gamma'-eutectics act as crack starters, thus initiating early failure. Moreover, the results indicate that remaining gamma/gamma'-eutectics can weaken the fatigue resistance even more than pores. Furthermore, the results confirm the beneficial effect of proper integrated hot isostatic pressing heat-treatments on the fatigue performance. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd.

【 授权许可】

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