Prediction the effect of ta on the mechanical behaviour and experimental validation of novel six component Fe-co-Ni-Cr-V-ta eutectic high entropy alloys

Abstract

Eutectic high entropy alloys (EHEAs) with six components (Fe, Co, Ni, Cr, V and Ta) have been designed and developed via vacuum arc melting route, following the guidance of the results from ANSYS Fluent and ThermoCalc simulations. The outcome of the simulation results shows that the addition of Ta increases the solidification time from 0.21 s to 0.24 s. By varying the Ta content, the cooling curve slope and the development of the solid-liquid interface at the two-phase existence are linear with the various slopes. The phase evolution has been predicted using CALPHAD approach which shows that when 10 at. % Ta is added, the microstructure changes from hypoeutectic to hypereutectic with the presence of FCC and Laves phases. Additionally, the eutectic mixture (L → FCC + Laves), consisting of the hard Laves phase and the ductile FCC phase is confirmed by the experimental results. The studied alloys exhibit better mechanical properties, such as an increase in tensile strength, yield strength, and microhardness from 480 MPa to 230 MPa, and 216.17 HV to 1120 MPa, 950 MPa, and 411.53 HV respectively along with the reduction in elongation from 53.1% to 31.2% by the addition of Ta content from 2.5 at. % to 10 at. %. The predicted simulated results using ThermoCalc and ANSYS Fluent softwares are well supported by the experimental findings. © 2024 Elsevier Ltd