Fatigue behavior of high-entropy alloys: A review

Fatigue failures cost approximately 4% of the United States' gross domestic product (GDP). The design of highly fatigue-resistant materials is always in demand. Different from conventional strategies of alloy design, high-entropy alloys (HEAs) are defined as materials with five or more principal elements, which could be solid solutions. This locally-disordered structure is expected to lead to unique fatigue-resistant properties. In this review, the studies of the fatigue behavior of HEAs during the last five years are summarized. The four-point-bending high-cycle fatigue coupled with statistical modelling, and the fatigue-crack-growth behavior of HEAs, are reviewed. The effects of sample defects and nanotwins-deformation mechanisms on four-point-bending high-cycle fatigue of HEAs are discussed in detail. The influence of stress ratio and temperature on fatigue-crack-growth characteristics of HEAs is also discussed. HEAs could exhibit comparable or greater fatigue properties, relative to conventional materials. Finally, the possible future work regarding the fatigue behavior of HEAs is suggested.