Additive manufacturing of multi-scale heterostructured high-strength steels

Abstract

Additive manufacturing (AM) enables the processing of heterogeneous materials with customised architectures to improve strength-ductility synergy. Herein, layerwise-heterostructured high-strength steels were processed by AM of two steel powders following the designed architectures. The fabricated high-strength steels with hierarchical heterogeneous characteristics at the layer, melt-pool and grain scales, exhibit good strength-ductility combination, reaching a strength of 1.32 GPa together with an elongation of 7.5%. The increased strength attributes to hetero-deformation induced strengthening. In-situ deformation monitoring reveals many unique deformation bands in heterostructure materials, which delays necking and improves ductility. The findings demonstrate a novel potential approach to circumvent material property trade-offs.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

Additively manufactured heterogeneous materials with controllable architectures achieved a good strength-ductility combination; the underlying strengthening mechanism and unique deformation behaviour are revealed.

KEYWORDS:

• Laser aided additive manufacturing
• heterogeneous materials
• multi-material
• deformation behaviour
• architectures

Acknowledgements

This research was financially supported by the Agency for Science, Technology and Research (A*Star), Singapore, under the IAF-PP program (No: A1893a0031).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was financially supported by the Agency for Science, Technology and Research (A*Star), Singapore, under the IAF-PP program “Integrated large format hybrid manufacturing using wire-fed and powder-blown technology for LAAM process”, Grant No: A1893a0031.