Investigation of the evolution and strengthening effect of aluminum carbide for in-situ preparation of carbon nanosheets/aluminum composites

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 764; p. 138139
• Main Authors: Liu, Xinghai, Liu, Enzuo, Li, Jiajun, He, Chunnian, Zhao, Naiqin
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 09.09.2019; Elsevier BV
• Subjects: Aluminum base alloys; Aluminum carbide; Aluminum composites; Aluminum matrix composites; Annealing; Carbon; Carbon nanosheets; Controllability; Elongation; Evolution; Grain refinement; Interface; Interface reactions; Interfacial bonding; Investigations; Load transfer; Mechanical properties; Metal matrix composites; Nanomaterials; Nanosheets; Particulate composites; Strengthening mechanism; Tensile strength; Thermal expansion; Wettability; Aluminum matrix composites; Mechanical properties; Carbon nanosheets; Interface; Strengthening mechanism
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2019.138139

The interface plays a vital role in determining the microstructure and mechanical properties of metal matrix composites. The interfacial reactant, aluminum carbide (Al4C3), has a great influence on the mechanical properties of carbon nanomaterials reinforced aluminum matrix composites (C/Al). However, due to the relatively weak controllability of Al–C interfacial reaction by traditional ex-situ methods, there is a lack of comprehensive study on the evolution and strengthening effects of Al4C3 so far. In this study, Al4C3 nanophase was produced by an appropriate annealing treatment from 500 °C to 630 °C in in-situ synthesized carbon nanosheets/aluminum composites (CNS/Al). The evolution and strengthening effects of Al4C3 was investigated comprehensively. It was found that the formation of Al4C3 plays a vital role in reducing the interfacial thermal expansion and improving the Al–C interfacial wettability. Thereby, a robust interfacial bonding among CNS, Al4C3 and Al forms, resulting in the improvement of tensile strength of the composites. The tensile strength of the 1.0 wt%-CNS/Al composite after 30 min annealing at 600 °C reaches 245 MPa, which is ~113% higher than pure Al. The 22.3% of elongation exhibits a favorable strength-ductility balance. The main strengthening mechanisms are the Orowan dislocation strengthening, load transfer and grain refinement. The evolution of CNS and Al4C3 combined with their strengthening contributions were quantitatively investigated in detail.