Additive Manufacturing of High-Entropy Alloys

Additive manufacturing of high-entropy alloys represents a convergence of advanced metallurgical design and digital fabrication technologies. High-entropy alloys are multi-principal-element systems that derive exceptional mechanical, thermal and corrosion-resistant properties from their high configurational entropy. When processed by techniques such as laser powder bed fusion, directed energy deposition or binder jetting, these alloys exhibit tailored microstructures characterised by refined grains, controlled phase distributions and minimal defects. Rapid solidification inherent to additive processes enables fine cellular or dendritic morphologies, while retained residual stresses, porosity and interlayer bonding remain critical challenges. Recent advances demonstrate the potential to produce complex geometries, functional gradients and micro-lattices that leverage both alloy performance and design freedom. Applications span aerospace components, energy systems, biomedical implants and cryogenic devices, underscoring the global significance of this field. The ongoing integration of real-time monitoring, computational modelling and high-throughput screening promises to accelerate the optimisation of feedstock, process parameters and post-processing treatments, forging a path towards industrial adoption of high-entropy alloy manufacturing at scale.

Research from Nature Portfolio

A novel ink-extrusion approach has been developed to fabricate CoCrFeNi high-entropy alloy micro-lattices without the use of lasers. This method employs a blend of metal oxide nanopowders which are co-reduced, inter-diffused and sintered to near-full density. In situ diffraction studies reveal a complex phase evolution from oxide precursors to a face-centred-cubic equiatomic alloy, and the printed micro-lattices achieve over 99.5% relative density with strut diameters down to 100 µm, demonstrating excellent mechanical performance at ambient and cryogenic temperatures.

Selective laser melting has been applied to equiatomic CoCrFeMnNi high-entropy alloys to produce single-phase, face-centred-cubic structures with epitaxial grain growth. The as-built material features high dislocation densities and fine oxide precipitates, which confer outstanding compressive strength and ductility across a wide temperature range. Deformation mechanisms transition from slip and twinning at lower temperatures to slip and partial recrystallisation at elevated temperatures, highlighting the interplay between processing-induced microstructure and mechanical response.

Additive Manufacturing of High-Entropy Alloys publication trend

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

Technical terms

Additive Manufacturing (AM): A suite of layer-by-layer fabrication processes that build components directly from digital models.

High-Entropy Alloy (HEA): An alloy composed of five or more principal elements in near-equiatomic ratios, stabilised by high configurational entropy.

Laser Powder Bed Fusion (LPBF): An AM technique where a laser selectively fuses metal powder layer by layer under a controlled atmosphere.

Directed Energy Deposition (DED): A process that melts and deposits feedstock material simultaneously by using a focused energy source.

Binder Jetting: An AM method that selectively deposits a liquid binder onto a powder bed, followed by sintering to form a solid part.

References

1. Additive manufacturing of high-entropy alloys: Current status and challenges. Smart Materials in Manufacturing (2024).
2. 3D ink-extrusion additive manufacturing of CoCrFeNi high-entropy alloy micro-lattices. Nature Communications (2019).
3. Superior Temperature-Dependent Mechanical Properties and Deformation Behavior of Equiatomic CoCrFeMnNi High-Entropy Alloy Additively Manufactured by Selective Laser Melting. Scientific Reports (2020).
4. Additive manufactured high entropy alloys: A review of the microstructure and properties. Materials & Design (2022).