TY - JOUR
T1 - Alloy design, micromechanical and macromechanical properties of CoCrFeNiTax eutectic high entropy alloys
AU - Ai, Cheng
AU - He, Feng
AU - Guo, Min
AU - Zhou, Jian
AU - Wang, Zhijun
AU - Yuan, Zhanwei
AU - Guo, Yajie
AU - Liu, Yinliang
AU - Liu, Lin
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/2/25
Y1 - 2018/2/25
N2 - Based on binary phase diagrams and thermodynamic calculation, CoCrFeNiTax (x = 0.1, 0.3, 0.43, 0.5 and 0.7) eutectic high entropy alloys were designed. With increasing Ta content, as-cast microstructure changed from hypoeutectic (primary γ phase) to eutectic and to hypereutectic (primary Laves phase), and CoCrFeNiTa0.43 eutectic alloy was composed of γ phase with face-center cubic (FCC) structure and C14 type Laves phase with hexagonal close-packed (HCP) structure. Volume fraction of Laves phase increased with increasing Ta content, and thus microhardness was basically positive correlation with Ta content. Meanwhile, microhardness and elastic modulus of primary phase increased from primary γ phase to primary Laves phase, while hardness and elastic modulus of eutectic phases firstly decreased and then increased with increasing Ta content. In addition, based on nanoindentation load-displacement curves, the reverse analysis algorithms were used to obtain initial yield stress σy and strain hardening exponent n of primary γ phase and eutectic phases. Moreover, with increasing Ta content, the plasticity of CoCrFeNiTax alloys decreased, while the compression strength firstly increased and then decreased, and CoCrFeNiTa0.43 EHEA showed relatively high strength (2377 MPa) and relatively high plastic strain (17.5%).
AB - Based on binary phase diagrams and thermodynamic calculation, CoCrFeNiTax (x = 0.1, 0.3, 0.43, 0.5 and 0.7) eutectic high entropy alloys were designed. With increasing Ta content, as-cast microstructure changed from hypoeutectic (primary γ phase) to eutectic and to hypereutectic (primary Laves phase), and CoCrFeNiTa0.43 eutectic alloy was composed of γ phase with face-center cubic (FCC) structure and C14 type Laves phase with hexagonal close-packed (HCP) structure. Volume fraction of Laves phase increased with increasing Ta content, and thus microhardness was basically positive correlation with Ta content. Meanwhile, microhardness and elastic modulus of primary phase increased from primary γ phase to primary Laves phase, while hardness and elastic modulus of eutectic phases firstly decreased and then increased with increasing Ta content. In addition, based on nanoindentation load-displacement curves, the reverse analysis algorithms were used to obtain initial yield stress σy and strain hardening exponent n of primary γ phase and eutectic phases. Moreover, with increasing Ta content, the plasticity of CoCrFeNiTax alloys decreased, while the compression strength firstly increased and then decreased, and CoCrFeNiTa0.43 EHEA showed relatively high strength (2377 MPa) and relatively high plastic strain (17.5%).
KW - Compression properties
KW - Elastic modulus
KW - Eutectic high entropy alloys
KW - Hardness
KW - Microstructure
UR - http://www.scopus.com/inward/record.url?scp=85037673462&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2017.12.015
DO - 10.1016/j.jallcom.2017.12.015
M3 - 文章
AN - SCOPUS:85037673462
SN - 0925-8388
VL - 735
SP - 2653
EP - 2662
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -