TY - JOUR
T1 - The determining role of carbon addition on mechanical performance of a non-equiatomic high-entropy alloy
AU - Li, Xiaolin
AU - Hao, Xiaoxiao
AU - Jin, Chi
AU - Wang, Qi
AU - Deng, Xiangtao
AU - Wang, Haifeng
AU - Wang, Zhaodong
N1 - Publisher Copyright:
© 2021
PY - 2022/5/30
Y1 - 2022/5/30
N2 - The mechanical properties and deformation mechanism of a C-doped interstitial high-entropy alloy (iHEA) with a nominal composition of Fe49.5Mn29.7Co9.9Cr9.9C1 (at.%) were investigated. An excellent combination of strength and ductility was obtained by cold rolling and annealing. The structure of the alloy is consisted of FCC matrix and randomly distributed Cr23C6. For gaining a better understanding of deformation mechanism, EBSD and TEM were conducted to characterize the microstructure of tensile specimens interrupted at different strains. At low strain (2%), deformation is dominated by dislocations and their partial slip. With the strain increase to 20%, deformation-driven athermal phase transformation and dislocations slip are the main deformation mechanism. While at high strain of 35% before necking, deformation twins have been observed besides the HCP phase. The simultaneous effect of phase transformation (TRIP effect) and mechanical twins (TWIP effect) delay the shrinkage, and improve the tensile strength and plasticity. What's more, compared with the HEA without C addition, the yield strength of the C-doped iHEA has been improved, which can be attributed to the grain refinement strengthening and precipitation hardening. Together with the lattice friction and solid solution strengthening, the theoretical calculated values of yield strength match well with the experimental results.
AB - The mechanical properties and deformation mechanism of a C-doped interstitial high-entropy alloy (iHEA) with a nominal composition of Fe49.5Mn29.7Co9.9Cr9.9C1 (at.%) were investigated. An excellent combination of strength and ductility was obtained by cold rolling and annealing. The structure of the alloy is consisted of FCC matrix and randomly distributed Cr23C6. For gaining a better understanding of deformation mechanism, EBSD and TEM were conducted to characterize the microstructure of tensile specimens interrupted at different strains. At low strain (2%), deformation is dominated by dislocations and their partial slip. With the strain increase to 20%, deformation-driven athermal phase transformation and dislocations slip are the main deformation mechanism. While at high strain of 35% before necking, deformation twins have been observed besides the HCP phase. The simultaneous effect of phase transformation (TRIP effect) and mechanical twins (TWIP effect) delay the shrinkage, and improve the tensile strength and plasticity. What's more, compared with the HEA without C addition, the yield strength of the C-doped iHEA has been improved, which can be attributed to the grain refinement strengthening and precipitation hardening. Together with the lattice friction and solid solution strengthening, the theoretical calculated values of yield strength match well with the experimental results.
KW - Interstitial high-entropy alloy
KW - Mechanical properties
KW - Mechanical twins
KW - Phase transformation
KW - Precipitation strengthening
UR - http://www.scopus.com/inward/record.url?scp=85120078038&partnerID=8YFLogxK
U2 - 10.1016/j.jmst.2021.09.005
DO - 10.1016/j.jmst.2021.09.005
M3 - 文章
AN - SCOPUS:85120078038
SN - 1005-0302
VL - 110
SP - 167
EP - 177
JO - Journal of Materials Science and Technology
JF - Journal of Materials Science and Technology
ER -