Synergistic strengthening effect of alumina anchored graphene nanosheets hybrid structure in aluminum matrix composites

Abstract

The microstructure design of graphene based reinforcement is an effective route to obtain graphene/aluminum composites with good mechanical properties. In this study, alumina anchored on graphene nanosheets hybrid (Al₂O₃@GNS) was in situ synthesized by a sodium chloride template-assisted high-temperature calcination strategy. Al₂O₃@GNS was used as a reinforcement to fabricate aluminum matrix composites (Al₂O₃@GNS/Al) by flake powder metallurgy (FPM) route. It was found that Al₂O₃@GNS was homogenously distributed and a relatively obvious synergistic strengthening effect was acquired by employing Al₂O₃@GNS as reinforcement of the composites. ∼1.0 vol%-Al₂O₃@GNS/Al composite obtained the maximum tensile strength of 359 MPa, an ∼131.6% improvement superior to pure Al. The strengthening efficiency of Al₂O₃@GNS is higher than those reinforced by individual GNS, Al₂O₃ or its simple mixture. An elongation of 11.2% was achieved in the ∼ 1.0 vol%-Al₂O₃@GNS/Al composite, exhibiting a favorable strength-ductility synergy. The synergistic strengthening effect was attributed to the formation of an interlocked network of Al₂O₃@GNS, which was beneficial to improve the load transfer efficiency from the matrix to reinforcement in the composites.

Keywords:

• Al₂O₃@GNS hybrid
• composite materials
• mechanical properties
• synergistic strengthening

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors acknowledge the financial support by the National Key R&D Program of China (No. 2017YFB0703101) and the National Natural Science Foundation of China (No. 51422104, No. 51472177, No. 51531004, No.5153000279).