Microstructure evolution and deformation mechanism of coherent L12-strengthened high-entropy alloy during sliding wear

Yang，Lu1; Wei，Chengxia1; Liang，Dingshan1; Jiang，Feilong1; Cheng，Zhuo1; Luan，Junhua2; Jiao，Zengbao3; Ren，Fuzeng1

2023-05-01

10.1016/j.compositesb.2023.110651

COMPOSITES PART B-ENGINEERING   Impact Factor & Quartile

1359-8368

Face-centered-cubic high-entropy alloys (HEAs) strengthened with coherent ordered nanoprecipitates have demonstrated excellent strength-ductility synergy, even at elevated temperature. However, there still lacks fundamental understanding on their microstructure evolution and deformation mechanisms during dry sliding wear. Herein, we systematically investigated the friction and wear behaviors of CoCrNi(AlNb) alloy with high-density coherent L1 nanoprecipitates during sliding at room and elevated temperatures, with particular focus on wear-induced microstructure evolution. The alloy shows a low wear rate of 1.80 × 10 mm/(N⋅m) at room temperature (RT) and even an ultralow wear rate of the order of 10 mm/(N⋅m) at 600 °C. Detailed TEM analyses reveal that sliding-induced stacking faults (SFs) and dislocation cells play important roles in the formation of the gradient microstructure at RT and 600 °C, respectively. The superior wear resistance at RT is mainly attributed to the precipitation strengthening of high-density coherent L1 phase and the dynamic work-hardening of SF networks near the sliding surface. However, at 600 °C, the reduced wear rates and coefficients of friction are associated with the formation of glaze layer and the high resistance to thermal softening. This work provides significant insight into the sliding-induced microstructure evolution and deformation mechanism of L1-strengthened high-entropy alloys during sliding wear.

Deformation mechanism High-entropy alloy Microstructure evolution Sliding wear

English

First ; Corresponding

MATERIALS SCIENCE

2-s2.0-85149401702

Scopus

1.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,China
2.Department of Materials Science and Engineering,City University of Hong Kong,Hong Kong,China
3.Department of Mechanical Engineering,The Hong Kong Polytechnic University,Hong Kong,China

Yang，Lu,Wei，Chengxia,Liang，Dingshan,et al. Microstructure evolution and deformation mechanism of coherent L12-strengthened high-entropy alloy during sliding wear[J]. COMPOSITES PART B-ENGINEERING,2023,256.

Yang，Lu.,Wei，Chengxia.,Liang，Dingshan.,Jiang，Feilong.,Cheng，Zhuo.,...&Ren，Fuzeng.(2023).Microstructure evolution and deformation mechanism of coherent L12-strengthened high-entropy alloy during sliding wear.COMPOSITES PART B-ENGINEERING,256.

Yang，Lu,et al."Microstructure evolution and deformation mechanism of coherent L12-strengthened high-entropy alloy during sliding wear".COMPOSITES PART B-ENGINEERING 256(2023).