Microstructural and Mechanical Property Engineering in Additive Manufacturing

Additive manufacturing has matured into a versatile platform for the fabrication of complex metallic components, yet the attainment of wrought-equivalent microstructures and mechanical performance remains a central challenge. Engineering strategies now encompass both in situ and post-build interventions to tailor grain morphology, phase distribution and residual stress states. Control of thermal gradients through parameter optimisation in laser-based and wire-fed processes influences solidification structure, yielding either columnar growth or refined equiaxed grains. Layer-wise deformation techniques, such as inter-pass rolling, suppress anisotropic columnar textures and introduce beneficial work-hardening, while surface treatments and heat treatments further reduce residual stresses and unlock latent mechanical potential. Advanced characterisation using electron backscatter diffraction and diffraction-based residual stress mapping provides unprecedented insight into the coupling between process, structure and properties. The convergence of process modelling, experimental realisation and hybrid manufacturing routes is driving the production of functionally optimised parts for aerospace, energy and biomedical applications on a global scale.

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Research from all publishers

Recent work on nickel-based superalloys produced by wire-fed additive processes has demonstrated that inter-pass rolling, followed by solutionising and ageing, can mitigate the formation of deleterious intermetallic phases, refine prior-β grains and lead to a more uniform stress profile, thereby enhancing tensile strength and fatigue resistance. In parallel, studies on stainless steel components have shown that post-build cold rolling to high plastic strains combined with annealing at elevated temperatures can eliminate build-direction texture, yielding isotropic elastic and plastic properties that meet or exceed those of conventionally wrought material. Complementary numerical investigations have also been reported, in which coupled deposition–rolling models guide the design of roller geometries and sequences to maximise plastic strain penetration, suppress tensile residual stresses and minimise distortion in large-scale structures.

Microstructural and Mechanical Property Engineering in Additive Manufacturing publication trend

The graph below shows the total number of articles in microstructural and mechanical property engineering in additive manufacturing across all publications each year (not limited to Nature Index journals).

Technical terms

Residual stress: Locked-in internal stress arising from thermal or mechanical histories that can cause distortion, fatigue or cracking.

Inter-pass rolling: Application of mechanical deformation to a layer between deposition steps to refine grain structure and relieve stress.

Equiaxed grains: Crystallites of approximately equal dimensions in all directions, promoting isotropic mechanical properties.

Columnar grains: Elongated crystallites that grow in a preferred direction, often leading to anisotropic behaviour.

Texture: Preferred orientation of crystallographic planes within a polycrystal that influences anisotropy in mechanical and physical properties.

References

1. Study of residual stress and microstructural evolution in as-deposited and inter-pass rolled wire plus arc additively manufactured Inconel 718 alloy after ageing treatment. Materials Science and Engineering A (2021).
2. Post-build thermomechanical processing of wire arc additively manufactured stainless steel for improved mechanical properties and reduction of crystallographic texture. Additive Manufacturing (2022).
3. Numerical Investigation of the Effect of Rolling on the Localized Stress and Strain Induction for Wire + Arc Additive Manufactured Structures. Journal of Materials Engineering and Performance (2019).
4. Modelling and optimising hybrid process of wire arc additive manufacturing and high-pressure rolling. Materials & Design (2022).