Hierarchical heterostructure induces high entropy alloy to achieve high strength and ductility
作者
单位
a Beijing Key Lab of Microstructure and Property of Advanced Materials、School of Physics and Optoelectronic Engineering、Beijing University of Technology、Beijing 100124、China b Department of Mechanical Engineering、The University of Western Australia、Perth、WA 6009、Australia c Department of Materials Science & Engineering、Southern University of Science and Technology、Shenzhen 518055、China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
Heterostructures have achieved surprising performance in breaking the strength-ductility trade -off. In this paper, we successfully introduced hierarchical multiple component microstructure into the newly designed dual -phase (FeCoNiV)96Al3Ti alloy by tuning composition and adjusting thermal -mechanical process, including heterogeneous precipitation of fine B2 (~220 nm) precipitates in the L12 matrix. Within B2 island, there are L12 grains (~722nm) and B2 grains (~900nm) with small grain size, among which the B2 grains have a fine microstructure of spinodal decomposition (~1 7 nm). This hierarchical multiple hetero -structures result in (FeCoNiV)96Al3Ti alloy achieving extraordinary combination of strength and ductility at both 298 K and 77 K, i.e., the ultimate tensile strength of 1750 MPa and the tensile elongation of 22% at 298 K and the ultimate tensile strength of 2100 MPa and the tensile elongation of 26% at 77 K. The remarkable combination of strength and ductility at both cryogenic and room temperatures is attributed to the synergistic effect of multiple deformation mechanisms, namely Orowan-bypass mechanism, stacking faults, and Lomer -Cottrell locks, and nanotwins. This study provides a new approach for tailoring the microstructure of alloys and designing hetero-structured materials.