Fatigue Behavior of High-Entropy Alloys

Fatigue performance is a critical determinant for structural alloys in demanding applications such as aerospace, energy and transportation. High-entropy alloys (HEAs), characterised by multiple principal elements and high configurational entropy, have emerged as promising candidates for fatigue-resistant materials. Their complex chemistry yields a range of microstructural mechanisms—including solid-solution strengthening, transformation-induced plasticity (TRIP), twinning-induced plasticity (TWIP) and precipitation-strengthening phases—that interact under cyclic loading. Grain size refinement, controlled phase stability and engineered intermetallic precipitates have been shown to influence crack initiation, propagation and overall fatigue life. Recent studies reveal that metastability of face-centred cubic matrices, reversible martensitic transformations and ductile-transformable intermetallic phases can delay crack nucleation, promote crack-tip blunting and enhance crack-growth resistance. Collectively, these insights point to a design paradigm in which alloy chemistry, processing route and microstructural architecture are co-optimised to achieve exceptional fatigue endurance.

Research from Nature Portfolio

Recent studies have demonstrated that embedding ductile-transformable B2-ordered precipitates within a high-entropy matrix markedly improves fatigue-crack-initiation resistance at low strain amplitudes. Real-time in situ neutron diffraction and transmission-electron microscopy revealed that cyclic deformation proceeds via a synergy of dislocation slip, precipitation strengthening, deformation twinning and reversible martensitic transformation of the B2 phase. Crystal-plasticity modelling and Monte Carlo simulations further illustrated how elastic compliance, plastic deformability and phase reversion collectively suppress crack nucleation and retard early crack growth. This work establishes a blueprint for fatigue-resistant alloys through the deliberate incorporation of multicomponent intermetallic phases that combine strength with ductility under cyclic stress.

Fatigue Behavior of High-Entropy Alloys publication trend

The graph below shows the total number of articles in fatigue behavior of high-entropy alloys across all publications each year (not limited to Nature Index journals).

Technical terms

Low-cycle fatigue (LCF): Cyclic loading characterised by high strain amplitudes and relatively low number of cycles to failure.

High-cycle fatigue (HCF): Cyclic loading at low strain amplitudes where failure arises after a large number of cycles.

Transformation-induced plasticity (TRIP): Deformation mechanism in which a metastable phase transforms to a martensitic structure under stress, absorbing energy and enhancing ductility.

Deformation twinning (TWIP): Slip system activation that forms nanoscale twin lamellae, contributing to work hardening and resistance to crack propagation.

B2 precipitates: Ordered intermetallic phases with a simple cubic structure that can undergo reversible transformations under cyclic loading, reinforcing the matrix.

Crack-tip blunting: Localised plastic deformation at a crack tip that reduces stress concentration and slows crack growth.

References

1. Enhancing fatigue life by ductile-transformable multicomponent B2 precipitates in a high-entropy alloy. Nature Communications (2021).
2. Metastability-assisted fatigue behavior in a friction stir processed dual-phase high entropy alloy. Materials Research Letters (2018).
3. Enhancement of fatigue resistance by overload-induced deformation twinning in a CoCrFeMnNi high-entropy alloy. Acta Materialia (2020).
4. Fatigue dataset of high-entropy alloys. Scientific Data (2022).