Strengthening of mechanical and tribological properties in CrFeCuMnNi high entropy alloy through dispersion of TiO2 reinforcement via powder metallurgy processes

The present study reports the effect of TiO₂ reinforcement on the phase, microstructure, mechanical and tribological properties of CrFeCuMnNi/TiO₂ high entropy alloy composites (HEACs) processed by powder metallurgy. The results reveal the formation of single-phase face-centered cubic (FCC) structure after 30 h of milling in the original HEA, while TiO₂ peaks in the HEACs indicate uniform distribution. After sintering, multiple phases including FCC, Cr-rich, Cr₂O₃ were observed. The hardness of HEAs increased from 330±10 to 440±10 HV and compressive yield strength increased from 480 to 760 MPa while scarifying the strain from 43.5 to 21 % with TiO₂ content. The addition of TiO₂ content slightly reduces the coefficient of friction and specific wear rate decreased by 45.16 % due to increased hardness and formation of stable oxide layer on the worn surface inhibits plastic deformation. The addition of TiO₂ reduces the dominance of abrasive and adhesive wear and enhances the strength of HEACs.