TY - JOUR
T1 - Hetero-deformation promoted strengthening and toughening in BCC rich eutectic and near eutectic high entropy alloys
AU - Chung, D. H.
AU - Lee, J.
AU - He, Q. F.
AU - Kim, Y. K.
AU - Lim, K. R.
AU - Kim, H. S.
AU - Yang, Y.
AU - Na, Y. S.
N1 - Funding Information:
This work was financially supported by the National Research Foundation of Korea (No. NRF-2021R1A6A3A0108674211 ), the Fundamental Research Program of the Korean Institute of Materials Science (No. PNK8730), and by Research Grant Council (RGC), Hong Kong Government, through General Research Fund (Nos. CityU11213118 , CityU11200719 and CityU11209317 )
Publisher Copyright:
© 2022
PY - 2023/5/20
Y1 - 2023/5/20
N2 - Heterostructured eutectic high-entropy alloys (EHEAs) have attracted significant attention owing to their novel properties, such as balanced combinations of strength and fracture toughness. However, the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated. In this study, we developed a series of dual-phase Al(18–2x)Co30Cr(11+x)Fe(11+x)Ni30 (x= -1, 0, 1) eutectic and near-eutectic HEAs containing face-centered cubic (FCC) and body-centered cubic (BCC) phases. Despite the high amount of BCC, which is referred to as the brittle phase, newly developed EHEAs exhibited superior fracture toughness. Interestingly, we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness, outperforming our off-eutectic and other previously reported HEAs. By combining experiments and theoretical models, we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformation-induced (HDI) strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.
AB - Heterostructured eutectic high-entropy alloys (EHEAs) have attracted significant attention owing to their novel properties, such as balanced combinations of strength and fracture toughness. However, the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated. In this study, we developed a series of dual-phase Al(18–2x)Co30Cr(11+x)Fe(11+x)Ni30 (x= -1, 0, 1) eutectic and near-eutectic HEAs containing face-centered cubic (FCC) and body-centered cubic (BCC) phases. Despite the high amount of BCC, which is referred to as the brittle phase, newly developed EHEAs exhibited superior fracture toughness. Interestingly, we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness, outperforming our off-eutectic and other previously reported HEAs. By combining experiments and theoretical models, we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformation-induced (HDI) strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.
KW - Eutectic high entropy alloy
KW - Fracture toughness
KW - Hetero deformation induced strengthening
KW - Heterogeneous structure
KW - Misorientation angle
UR - http://www.scopus.com/inward/record.url?scp=85145578323&partnerID=8YFLogxK
U2 - 10.1016/j.jmst.2022.10.036
DO - 10.1016/j.jmst.2022.10.036
M3 - Article
AN - SCOPUS:85145578323
SN - 1005-0302
VL - 146
SP - 1
EP - 9
JO - Journal of Materials Science and Technology
JF - Journal of Materials Science and Technology
ER -