Influence of composition and annealing heat-treatment on the microstructural of TiVNbCr based High entropy alloys

In this study, TiVNbCr-based HEAs with Fe and Mn additions were produced by vacuum arc melting and subjected to heat treatment to investigate the influence of alloying and thermal processing on microstructures. CALPHAD calculations, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were employed to evaluate the microstructural characteristics. Results revealed that as-cast alloys predominantly exhibited body-centered cubic (BCC) dendrite regions with minimal to none interdendritic Laves phases, while Fe and Mn-rich compositions favored increased stabilization of C14 Laves phases. Heat treatment at 750°C enhanced atomic diffusion, promoting solute redistribution and significant growth of Laves phases, particularly in alloys enriched with Nb, Cr, Fe, and Mn. The findings highlight the critical role of composition and heat treatment in tailoring BCC/Laves phase balance within HEAS, offering pathways for designing HEAs with optimized hydrogen storage capacity, kinetics, and reversibility.