On the correlation between L12 nanoparticles and mechanical properties of (NiCo)52+2x(AlTi)4+2xFe29-4xCr15</ sub> (x=0-4) high-entropy alloys

作者：Peng, Hanlin; Hu, Ling^*; Li, Liejun^*; Gao, Jixiang; Zhang, Qi

来源：Journal of Alloys and Compounds, 2020, 817: 152750.

DOI：10.1016/j.jallcom.2019.152750

• High-entropy alloys
• Alloy design
• L1(2) nanoparticles
• Microstructure
• Mechanical properties
• Strengthening mechanisms

Different L1(2)-Ni-3(Ti, Al) phase contents in (NiCo)(52+2x)(AlTi)(4+2x)Fe29-4xCr15 (x = 0-4) high-entropy alloys are designed based on CALPHAD and its effects on mechanical properties are systematically studied. Results show that excellent combination of yield strength (635-753 MPa), ultimate tensile strength (1010-1074 MPa), and fracture strain (23-31%) could be obtained for high-entropy alloys (x = 2 and 3). Almost half of the yield strength comes from nano-sized L1(2)-type precipitates strengthening. The yield strength experienced sharp increment and the ductility showed an obvious decrease when the precipitated L1(2) phase increased in the range of 0-14.2 wt%, with corresponding Al and Ti concentrations in the range of x = 0-3. Furthermore, when the precipitated L1(2) phase exceeds 14.2 wt%, merely a slight increment in yield strength was observed, but the fracture strain declined to around 13%. The present results contribute to understanding the strengthening mechanisms of L1(2)-strengthened HEAs and may provide some reference for its application.

• 单位
  华中科技大学; 广东技术师范学院