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

作者：Xu, Z. Y.; Li, C. J.^*; Wang, Z.; Fang, D.; Gao, P.; Tao, J. M.; Yi, J. H.^*; Eckert, J.

来源：Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing , 2020, 796: 140067.

DOI：10.1016/j.msea.2020.140067

• Aluminum matrix composite (AMC)
• Carbon nanotubes (CNTs)
• Graphene oxide (GO)
• Bimodal grains

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 strainhardening 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 similar to 23.1%).