Enhanced strength and ductility of metal composites with intragranularly dispersed reinforcements by additive manufacturing

Abstract

Reinforcements in metal composites are usually dispersed at grain boundaries. We here show that the rapid solidification during laser additive manufacturing enables the spontaneous engulfment of reinforcing particles inside aluminum grains, which helps to decouple the stress concentration induced by grain boundaries and reinforcements. The additively manufactured TiB₂-Al composite possesses 30% increase in tensile strength and nearly tripled ductility as compared with composite obtained by the traditional method. Our experimental investigations indicate that the intragranular dispersion of particles not only inhibits crack nucleation but also promotes strain hardening, leading to the remarkably enhanced mechanical properties.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

Metal composite with intragranular dispersion of reinforcing particles can be achieved through additive manufacturing, which alleviates stress concentration and possesses much-improved ductility.

KEYWORDS:

• Additive manufacturing
• aluminum matrix composites
• intragranular dispersion
• tensile property

Disclosure statement

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

Additional information

Funding

This work was supported by the National Key Research and Development Program of China (No. 2021YFA1600704), the National Natural Science Foundation of China [grant number 52192595, 52171142], the Singapore Ministry of Education Academic Research Fund Tier 2 [grant number MOE-T2EP50120-0012].