Material Characterisation and Mechanical Properties of WNbMoVAl<sub>x</sub>Cr<sub>y</sub> (x=0.5, 1 y= 0.5, 1) Refractory High Entropy Alloys

Abstract

WNbMoVAlxCry RHEA series are consolidated via spark plasma sintering with using mechanically alloyed powders. Mechanical alloying of W NbMoVAlCr alloy was conducted for up to 8 hours at 2-hour intervals to determine the ideal alloying time. Mechanical alloying resulted in the formation of a single phase, with the disappearance of elemental peaks and flattening of peaks. XRD peaks revealed a body-centred cubic and Laves phases. SEM and point EDS results showed homogeneous distribution of elements. Mechanical alloying had a positive effect up to 6 hours, with the highest hardness value of 12.57 GPa. The highest compressive strength at room temperature was 1397 MPa, while the lowest strength at 900°C was 172 MPa. Al and Cr had no clear effect on hardness and compression strength, with no clear trend on improvement or reduction in mechanical properties.