Comparative Analysis of Wear Behavior of High Entropy Alloy (TiVNbCrAl) and Ti-based Conventional Alloy (TiNbCrCoAl)

Abstract

This research examined the relationships between processing, structure, and property at both room temperature and increased temperature for two BCC high entropy alloy (TiVNbCrAl) and Ti-based conventional alloy (TiNbCrCoAl) prepared using standard arc melting. Both alloys have been determined to have the BCC single-phase solid solution structure. To investigate the hardness and tribological behavior and processes at room temperature and above, microindentation and sliding wear experiments were undertaken. Both alloys display comparable friction behavior when sliding at room temperature, with an average steady-state coefficient of friction (COF) of 0.6. When sliding temperatures rise to 302 °C, the average COF for HEA (TiVNbCrAl) has decreased to a lowest value of ~0.4 due to the creation of a persistent tribochemical layer made of Nb and Cr oxides amid the sliding surfaces, which lowers COF. Whereas, COF for Ti-based conventional alloy remains at higher values of ~0.65. Mechanistic wear analyses revealed that the formation of tribofilms with low interfacial shear strength inside the wear tracks was the cause of this. The tribofilms were identified to be mostly constituted by multi-element solid solution oxides, such as Ni2O5, Cr2O3, and NiO2, according to Raman spectroscopy. The Vickers microharness values for Ti-based conventional alloy is about 365±4 HV. Whereas, for high entropy alloy is about 572±12 HV due to the solid solution strengthening.