[SY-E7] Symposium E-7

[SY-E7] First-principles-based prediction of yield strength in the RhIrNiPdPtCu high entropy alloy

^○Binglun Yin, William A. Curtin (LAMMM, EPFL, Switzerland)

High entropy alloys (HEAs) are random solid solution alloys with 5 or more components, usually of near equi-composition. HEAs exhibit excellent mechanical properties, including high strength, high ductility, and high fracture toughness [1]. Guiding the design of new HEAs across the vast composition space requires an ability to compute necessary underlying material parameters via first-principle calculations. Here, a methodology is proposed to compute, via density functional theory (DFT), the elemental misfit volumes, as well as alloy lattice constant, elastic constants and stable stacking fault energy, in the fcc noble metal HEA RhIrNiPdPtCu [2]. These properties are then used in a recently developed solute strengthening model [3, 4] for temperature and strain-rate dependent yield strength, with the prediction of 563 MPa is in excellent agreement with the experimentally measured value of 527 MPa [5]. This methodology links the alloy composition with the yield strength prediction, indicating a general methodological path for exploring new potential high-strength HEAs in this and other alloy classes.


[1] D. B. Miracle and O. N. Senkov, Acta Mater. 122, 448 (2017).

[2] B. Yin and W. A. Curtin, in preparation.

[3] C. Varvenne, A. Luque, and W. A. Curtin, Acta Mater. 118, 164 (2016).

[4] C. Varvenne, G. P. M. Leyson, M. Ghazisaeidi, and W. A. Curtin, Acta Mater. 124, 660 (2017).

[5] S. Sohn, Y. Liu, J. Liu, P. Gong, S. Prades-Rodel, A. Blatter, B. E. Scanley, C. C. Broadbridge, and J. Schroers, Scr. Mater. 126, 29 (2017).