Plasma spheroidized MoNbTaTiZr high entropy alloy showing improved plasticity

Abstract

Refinement of the harder phase in two-phase MoNbTaTiZr high-entropy alloys (HEA) prepared by a powder metallurgy route has enhanced strength and plasticity of the alloy. The MoNbTaTiZr HEA powder used in this study was prepared by hydrogenation-dehydrogenation followed by plasma spheroidization, having an inherent dual-phase structure (bcc1 and bcc2) similar to the arc melted alloy of the same composition but with much finer morphology of the bcc2 phase. The homogenous and fine distribution of the harder Zr-rich phase (bcc2) with-10% volume fraction embedded inside the Ta-rich phase (bcc1) evaded the strength-ductility trade-off. The shear-band delocalization in the bcc1 matrix phase improved the strength as well as the plasticity of the alloy. The alloy has potential in biomedical implants because it shows excellent corrosion resistance and lower magnetic susceptibility, making it an MRI (magnetic resonance imaging)-friendly alloy.