Titanium-induced phase changes and tribological behavior in cantor-based high entropy alloys

This study systematically examines the effects of titanium (Ti) incorporation on the phase evolution, magnetic behavior, thermal stability, and tribological performance of Cantor-based FeCrCoNiMnTix (x = 0.25–1.00) high-entropy alloys (HEAs) synthesized via planetary mechanical alloying. Comprehensive characterization using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), static light scattering (SLS), and vibrating sample magnetometry (VSM) indicated that addition of Ti drove the transition from FCC-dominated to BCC-rich microstructures and promoted Laves phase formation. Thermodynamic predictions via JMatPro 7.0 corroborated the experimental findings, confirming the stability of multiphase structures at elevated temperatures. Mechanical alloyed powders were successfully deposited as coatings using spark plasma sintering (SPS) to ascertain their wear resistance, while magnetic characterization was performed for elucidating the phase behavior. The FeCrCoNiMnTi alloy (x = 1.00) exhibited a dominant BCC phase and the highest saturation magnetization (~ 55 emu/g). Thermal stability tests revealed that both Ti-free and Ti-containing alloys retained their phase structures after annealing at 900 °C. Tribological evaluations presented a progressive decline in wear rate from 9.00 × 10⁻⁵ to 3.78 × 10⁻⁵ mm³/N·m with increasing Ti content. This can be attributed to a synergistic hardening effect from the BCC matrix, Laves intermetallics, and in-situ formed carbide phases. These results highlight the potential of Ti-modified Cantor HEAs as promising candidates for wear-resistant coatings, emphasizing the critical role of compositional design in tailoring their structural and tribological properties.