Mechanical and electrical properties of copper-graphene nanocomposite fabricated by high pressure torsion

• Published in: Journal of alloys and compounds 2019-03, Vol.776, p.123-132
• Main Authors: Khobragade, Nidhi, Sikdar, Koushik, Kumar, Binod, Bera, Supriya, Roy, Debdas
• Format: Article
• Language: English
• Subjects: Bonding strength; Copper; Crystal dislocations; Dislocation pinning; Dislocations; Electrical conductivity; Electrical properties; Electrical resistivity; Graphene; Graphite; Hardness; Hardness testing; Heat conductivity; High pressure torsion; Metal matrix composites; Microstructure; Modulus of elasticity; Nanocomposites; Scanning electron microscopy; Theoretical density; Torsion; Transmission electron microscopy; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.10.139

Graphene reinforced Cu matrix composite was fabricated by consolidating mechanically mixed powder blend to 98% theoretical density by High Pressure Torsion (HPT). Microstructural characterization by scanning electron microscopy (SEM) elicits even distribution of the reinforcement phase into the matrix. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirms nanocrystalline microstructure and strong interfacial bonding between Cu and graphene. Addition of 10 wt % graphene yields maximum hardness (∼2.67 GPa) and Young's modulus (∼102.03 GPa). The increment in strength was attributed to the microstructural refinement and dislocation pinning at the strong matrix-reinforcement interface. The electrical conductivity of the Cu- 10 wt% graphene composite was found to be ∼87% IACS. Results indicated that HPT consolidation is an efficient mean for synthesizing Cu-graphene composite with improved strength (∼2 times higher hardness than pure Cu processed under similar condition) with negotiable conductivity. •Cu-graphene composite was fabricated by High Pressure Torsion (HPT).•Cu-10 wt% graphene composite shows high hardness (2.67 ± 0.08 GPa) and electrical conductivity ∼87% IACS.•TEM investigation shows strong Cu-graphene interface, which acts as barrier to dislocation motion.