Fatigue Behavior and Mechanisms of High-Entropy Alloys

Abstract

Fatigue failures of structural materials pose enormous risks to in-service structures, as well as human lives. The development of advanced durable structural materials with fatigue resistance has important social impact. The novel concept of high-entropy alloys (HEAs) has engendered considerable attention due to their exhibited unusual mechanical properties, and correspondingly opening a new road to design fatigue-resistant structural materials. The present work discusses and reviews the current findings on fatigue behavior and mechanisms of HEAs. Based on the understanding of fatigue-resistant favorable deformation mechanisms in HEAs, the perspectives from the viewpoint of materials design are provided to advance the development of fatigue-resistant HEAs, and future works are also suggested.

Fatigue Behavior of Medium Entropy Alloys AlCrFe₂Ni₂ and AlCrFe₂Ni₂Mo_0.1- A Comparison with Super Duplex Steel 1.4517

“…Furthermore, the planar mode weakens irreversible cyclic strain, accumulated ahead of the crack tip, and prevents fatigue crack propagation, both resulting in an enhanced resistance to fatigue failure [27]. Moreover, [9] designed strategies for developing advanced fatigue-resistant HEAs, based on the aspects of hierarchical microstructure, reversible planar slip, deformation twinning (TWIP) and transformation induced plasticity (TRIP), of which only the aspect of hierarchical microstructure was observed in the present study. Therefore, further studies could tackle the remaining aspects.…”

“…They offer a combination of high strength and ductility [4] as well as good corrosion and wear resistance [5,6]. Moreover, excellent fatigue properties [7][8][9][10] and good fracture toughness [11] have been reported for HEAs, making them suitable for many applications, which require a good balance between strength and ductility or toughness along with wear and corrosion resistance. Application examples are turbine blades, pumps, compressors, exhaust systems and structural applications [12,13].…”

“…Whereas, the characterization of the fatigue properties is key in the industrialization process of any new material, it is even more crucial for the above mentioned applications. Chen et al, Li et al, provide overviews of the fatigue relevant mechanisms in HEAs, including dislocation-evolution, deformation nano-twinning and twinning induced plasticity (TWIP) [7,9]. Moreover, the concept of transformation induced plasticity (TRIP) is well known in steels [18], but has also been reported for HEAs [9,19] and, together with ultra-fine grains, was shown to lead to exceptional fatigue properties [20].…”

“…Chen et al, Li et al, provide overviews of the fatigue relevant mechanisms in HEAs, including dislocation-evolution, deformation nano-twinning and twinning induced plasticity (TWIP) [7,9]. Moreover, the concept of transformation induced plasticity (TRIP) is well known in steels [18], but has also been reported for HEAs [9,19] and, together with ultra-fine grains, was shown to lead to exceptional fatigue properties [20]. Furthermore, crack initiation resistance, due to microstructural hierarchies [21,22] seems to be an important aspect, possibly enhancing fatigue properties of HEAs.…”