Tribological properties of high-entropy alloys: A review

Tribology, which is the study of friction, wear, and lubrication, largely deals with the service performance of structural materials. For example, newly emerging high-entropy alloys (HEAs), which exhibit excellent hardness, anti-oxidation, anti-softening ability, and other properties, enrich the wear-resistance alloy family. To demonstrate the tribological behavior of HEAs systematically, this review first describes the basic tribological characteristics of single-, dual-, and multi-phase HEAs and HEA composites at room temperature. Then, it summarizes the strategies that improve the tribological property of HEAs. This review also discusses the tribological performance at elevated temperatures and provides a brief perspective on the future development of HEAs for tribological applications.