In situ investigation of the deformation behaviors of Fe20Co30Cr25Ni25 and Fe20Co30Cr30Ni20 high entropy alloys by high-energy X-ray diffraction

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:795

Article

Xu, Ning¹  Li, Shilei¹  Li, Runguang¹  Zhang, Minghe¹  Yan, Zhiran¹  Cao, Yuxian¹  Nie, Zhihua²  Ren, Yang³  Wang, Yan-Dong¹ 

[1] Univ Sci & Technol Beijing, Beijing Adv Innovat Ctr Mat Genome Engn, State Key Lab Adv Met & Mat, Beijing 100083, Peoples R China

[2] Beijing Inst Technol, Sch Mat Sci & Engn, Beijing 100081, Peoples R China

[3] Argonne Natl Lab, Xray Sci Div, Adv Photon Source, Argonne, IL 60439 USA

关键词: High entropy alloys;    Transformation-induced plasticity;    High-energy X-ray diffraction;    Twinning-induced plasticity;   

DOI  :  10.1016/j.msea.2020.139936

来源: Elsevier

【 摘 要 】

In situ synchrotron-based high-energy X-ray diffraction (HE-XRD) technique was employed to investigate the mechanical behaviors and microstructural evolution of face-centered cubic (FCC) Fe20Co30Cr25Ni25 and Fe20Co30Cr30Ni20 high entropy alloys (HEAs) during tensile deformation. Fe20Co30Cr30Ni20 HEA has a good combination of strength (ultimate tensile strength of 864 +/- 35 MPa) and ductility (elongation of 0.627 +/- 0.021). The HE-XRD investigation reveals that Fe20Co30Cr30Ni20 HEA has the transformation-induced plasticity (TRIP) effect, which starts at a critical stress of similar to 555 MPa. Transmission electron microscopy confirmed this deformation-induced new phase is hexagonal-close-packed structured c-martensite, which follows an orientation relationship of {111}(gamma)/(0001)(epsilon), and < 110 >//[11 (2) over bar0](epsilon) with the FCC gamma matrix. The observation of deformation twins in the deformed samples of the two studied HEAs proves that twinning-induced plasticity (TWIP) effect occurs in both HEAs. The combination of TRIP and TWIP effects lead to the high strength, large ductility and improved strain hardening behavior of Fe20Co30Cr30Ni20 HEA.

【 授权许可】

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