MECHANICAL CHARACTERIZATION AND DEFORMATION MECHANISM OF TWINNED FeNiCrCoCu HIGH-ENTROPY ALLOY

Dinh-Quan Doan; Van-Ha Nguyen; Thi-Quy Vu; Huu-Chuyen Vu

Dinh-Quan Doan Hung Yen University of Technology and Education
Van-Ha Nguyen Hung Yen University of Technology and Education
Thi-Quy Vu Hung Yen University of Technology and Education
Huu-Chuyen Vu Hung Yen University of Technology and Education

Keywords: high-entropy alloy, nanoindentation, twinning, MD simulation

Abstract

Mechanical characteristics of twinned FeNiCrCoCu high-entropy alloy (HEA) under the nanoindentation are revealed through molecular dynamics simulation. The effect of twinning spacing on the plastic deformation behavior and crystal structure evolution are cautiously investigated. The results show that the indentation force and hardness values increase with decreasing the twinning spacing, which reveals the Hall-Petch relationship in the correlation between the material strength and twinning spacing. The deformation behavior suggests that the shear strain extends deep into the substrate along the twinning, which is shown by the shear bands. Besides, the twinning boundary plays a significant role in the plastic deformation mechanism of twined FeNiCrCoCu HEA, and the evolution of the planar defect and dislocation loop moving along the twinning. The result also shows that the Shockley dislocation accounts for a large proportion of total dislocations formed during the indentation for all specimens. Moreover, the dislocation density increases quickly during the loading phase, and then decreases rapidly during the unloading phase. Finally, the surface morphology shows that the largest pile-up height is for twinning spacings of 20.4 Å and 80.0 Å, while the smallest pile-up height is for twinning spacing of 54 Å.

References

Ye, Y. F., Wang, Q., Lu, J., Liu, C. T., & Yang, Y., High-entropy alloy: challenges and prospects. Materials Today, 2016, 19(6), pp. 349-362.

Deng, C., Wang, C., Chai, L., Wang, T., & Luo, J., Mechanical and chemical properties of CoCrFeNiMo0.2 high entropy alloy coating fabricated on Ti6Al4V by laser cladding. Intermetallics, 2022, 144, 107504.

Jin, G., Cai, Z., Guan, Y., Cui, X., Liu, Z., Li, Y., & Dong, M., High temperature wear performance of laser-cladded FeNiCoAlCu high-entropy alloy coating. Applied Surface Science, 2018, 445, pp. 113-122.

Takeuchi, A., Chen, N., Wada, T., Yokoyama, Y., Kato, H., Inoue, A., & Yeh, J. W., Pd20Pt20Cu20Ni20P20 high-entropy alloy as a bulk metallic glass in the centimeter. Intermetallics, 2011, 19(10), pp. 1546-1554.

Juan, C. C., Tsai, M. H., Tsai, C. W., Lin, C. M., Wang, W. R., Yang, C. C., ... & Yeh, J. W., Enhanced mechanical properties of HfMoTaTiZr and HfMoNbTaTiZr refractory high-entropy alloys. Intermetallics, 2015, 62, pp. 76-83.

Bhattacharjee, T., Wani, I. S., Sheikh, S., Clark, I. T., Okawa, T., Guo, S., ... & Tsuji, N., Simultaneous strength-ductility enhancement of a nano-lamellar AlCoCrFeNi2.1 eutectic high entropy alloy by cryo-rolling and annealing. Scientific reports, 2018, 8(1), pp. 1-8.

Deluigi, O. R., Pasianot, R. C., Valencia, F. J., Caro, A., Farkas, D., & Bringa, E. M., Simulations of primary damage in a High Entropy Alloy: Probing enhanced radiation resistance. Acta Materialia, 2021, 213, 116951.

Shen, Y., & Spearot, D. E., Mobility of dislocations in FeNiCrCoCu high entropy alloys. Modelling and Simulation in Materials Science and Engineering, 2021, 29(8), 085017.

Doan, D. Q., Fang, T. H., & Chen, T. H., Interfacial and mechanical characteristics of TiN/Al composites under nanoindentation. International Journal of Solids and Structures, 2021, 226, 111083.

Doan, D. Q., Fang, T. H., & Chen, T. H., Nanomachining characteristics of textured polycrystalline NiFeCo alloy using molecular dynamics. Journal of Manufacturing Processes, 2022, 74, pp. 423-440.

Doan, D. Q., Fang, T. H., Chen, T. H., & Bui, T. X., Effects of void and inclusion sizes on mechanical response and failure mechanism of AlCrCuFeNi2 high-entropy alloy. Engineering Fracture Mechanics, 2021, 252, 107848.

Doan, D. Q., Fang, T. H., & Chen, T. H., Structural transformation and strain localization at twin boundaries in Al0. 4CoCrFeNi high-entropy alloy. Applied Surface Science, 2022, 152383.

Thompson, A. P., Aktulga, H. M., Berger, R., Bolintineanu, D. S., Brown, W. M., Crozier, P. S.,... & Plimpton, S. J., LAMMPS-a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales. Computer Physics Communications, 2022, 271, 108171.

Polak, W. Z., Efficiency in identification of internal structure in simulated monoatomic clusters: Comparison between common neighbor analysis and coordination polyhedron method. Computational Materials Science, 2022, 201, 110882.