Compositional Modifications to Alter and Suppress Laves Phases in AlxCrMoTayTi Alloys

Abstract

Herein, the development of refractory complex concentrated alloys in the Al–Cr–Mo–Ta–Ti alloy system is reported. Alloys with modified Al and Ta concentrations are designed using CALPHAD tools and produced via arc melting and characterized in both as‐cast and annealed forms. Properties of the alloys, nature of the microstructures, and phase transformation behavior are described via X‐ray diffraction, microstructural characterization, microhardness, and differential scanning calorimetry. Two alloys, namely, Al0.25CrMoTa0.8Ti and Al0.75CrMoTa0.8Ti, are represented by a body‐centered‐cubic matrix phase after annealing, along with a secondary Cr–Ta Laves phase of the C15 and C14 polytypes, respectively. In as‐cast and annealed forms, the Al0.75CrMoTa0.45Ti alloy comprises a single‐bcc phase. Microhardness of the Laves phase containing alloys demonstrates susceptibility to cracking, whereas the Al0.75CrMoTa0.45Ti alloy displays high specific hardness, signs of ductility as evidenced by slip traces near indentations, and minimal scatter of hardness values.