Computational and experimental investigation of refractory high entropy alloy Mo15Nb20Re15Ta30W20

Uttam Bhandari, Congyan Zhang, Congyuan Zeng, Shengmin Guo, Shizhong Yang
2020 Journal of Materials Research and Technology  
j m a t e r r e s t e c h n o l . 2 0 2 0;9(x x):8929-8936 w w w . j m r t . c o m . b r a b s t r a c t In this study, refractory high entropy alloys (RHEAs) Mo were studied by applying the firstprinciples density functional theory (DFT) method. The DFT calculation was based on a large unit cell model of 100-atom supercell, with randomly distributed five element atoms. The mechanical properties of all three RHEAs were calculated and compared. Comparing with the other two RHEAs, Mo 15 Nb 20 Re
more » ... 5 Ta 30 W 20 possesses balanced mechanical properties with an optimized concentration of expensive Re element. We combined the DFT calculations of a supercell with Debye-Grüneisen theory to investigate the thermal properties of the two RHEAs was selected for further experimental exploration and the computational results were compared. The experimental study shows the existence of a single BCC structure of Mo 15 Nb 20 Re 15 Ta 30 W 20. The crystal structure, density, lattice parameter, and hardness predicted computationally are consistent with the experiment data. (S. Yang). resistant [7] in comparison with traditional alloys like Inconel 718 and Haynes 230. The extension of HEAs to refractory high entropy alloys (RHEAs) has been reported by Senkov et al. [3,8]. They found MoNbTaW and MoNbTaVW have higher melting points with good mechanical properties at high temperature compared to traditional alloys. Recently, other RHEAs such as TaNbHfZrTi [9], TiZrNbTaMo [10], AlNbTiVZr x [11], MoNbTaTiW [12] have been extensively studied. These RHEAs possess a single body centered cubic (BCC) structure with magnificent mechanical properties than HEAs with face centered cubic (FCC) structure. However, some RHEAs like NbCrMoTaTiZr [13], CrNbTiZr [14] and CrNbTiVZr [15] shows the existence of Laves phase in BCC matrix because of small atomic size of Cr in those RHEAs. The precipitation of Laves phase affects the mechanihttps://doi.
doi:10.1016/j.jmrt.2020.06.036 fatcat:qcwcm7pxebhapmkk6opw4uwm5a