As-cast Tix(AlVCr)100−x light-weight medium entropy alloys with high strength and uniform compressive plasticity

Abstract

The effect of Ti content on the microstructure and mechanical properties of as-cast light-weight Ti_x(AlVCr)_100−x medium entropy alloys was studied by compressive tests, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results suggest that yield strength increases and then decreases with the increment of Ti content. The Ti₆₀(AlVCr)₄₀ alloy has the best combination of high strength of 1204 MPa and uniform plastic strain of 70%, possessing a high specific yield strength of 255 MPa·cm³/g. The enhancement of strength is mainly attributed to the synergic effects of solid-solution and coherent nano-precipitation strengthening, while dislocation motion such as dislocation pinning, entanglement and dislocation cells significantly increases the strain-hardening capacity.