Balancing the strength and ductility of graphene oxide-carbon nanotube hybrid reinforced aluminum matrix composites with bimodal grain distribution

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 796; p. 140067
• Main Authors: Xu, Z.Y., Li, C.J., Wang, Z., Fang, D., Gao, P., Tao, J.M., Yi, J.H., Eckert, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 07.10.2020; Elsevier BV
• Subjects: Aluminum; Aluminum base alloys; Aluminum carbide; Aluminum matrix composite (AMC); Aluminum matrix composites; Bimodal grains; Carbon; Carbon nanotubes; Carbon nanotubes (CNTs); Ductility; Elongation; Grain structure; Graphene; Graphene oxide (GO); Hot extrusion; Powder metallurgy; Recrystallization; Strain hardening; Synergistic effect; Tensile strength; Yield strength; Carbon nanotubes (CNTs); Graphene oxide (GO); Aluminum matrix composite (AMC); Bimodal grains
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2020.140067

Graphene oxide-carbon nanotubes hybrid reinforced aluminum matrix composites (GO-CNT/Al) were prepared by powder metallurgy followed by hot extrusion. The strength of the composites was improved by the synergistic effect of carbon nanotubes, in-situ Al4C3 and graphene oxide. Moreover, due to the partially recrystallization of Al matrix promoted by Al4C3, the matrix exhibits a bimodal grain distribution, which helps to enhance strain-hardening and consequently uniform tensile ductility at high flow stresses. Hence the bimodal grain structure of the matrix combined with the nano-reinforcements leads to enhancing of the strength and ductility synergy. The composite shows a high tensile strength of 249 MPa (175 MPa of pure Al) and keeps almost similar tensile ductility with pure Al (uniform elongation of ~23.1%). •The structure changes of graphene oxide and carbon nanotubes during ball milling were revealed.•The influence of reinforcement dimension on the strengthening mechanism of aluminum matrix composites was emphasized.•The balance between strength and ductility is achieved by different dimension reinforcements and bimodal grain distribution.