Influence of Transition Metals Ti and Co on Interfacial Microstructure and Strength of Copper–graphene Composites
【Abstract】Transition metals Ti and Co were separately introduced into copper–graphene composites by matrix alloying and powder metallurgy methods. The effects of Ti and Co on the strength of copper–graphene composites were compared by tensile tests. The microstructure and interface structure of copper–graphene composites were characterized by a scanning electron microscope (SEM), a transmission electron microscope (TEM), and a Raman spectrometer. With the addition of Ti, a large number of TiC nanoparticles were formed on the interface, which promoted the interface bonding without increasing graphene defects, and the tensile strength increased from 223 MPa to 256 MPa. Nevertheless, amorphous carbon appeared at the interface of Co-doped composites. It increased graphene defects and was not conducive to play the role of strengthening phase and transferring interface load, resulting in the strength decreased from 223 MPa to 192 MPa.
【Keywords】 copper–graphene composites; Ti; Co; matrix alloying; powder metallurgy; interface structure; strength;
 Futami T, Ohira M, Muto H, et al. Indentation contact behavior of copper–graphite particulate composites: Correlation between the contact parameters and the electrical resistivity [J]. Carbon, 2008, 46 (4): 671–678.
 Chen F, Ying J, Wang Y, et al. Effects of graphene content on the microstructure and properties of copper matrix composites [J].Carbon, 2016, 96: 836–842.
 Salvo C, Mangalaraja R V, Udayabashkar R, et al. Enhanced mechanical and electrical properties of novel graphene reinforced copper matrix composites [J]. Journal of Alloys and Compounds, 2019, 777: 309–316.
 Chu K, Wang F, Li Y, et al. Interface structure and strengthening behavior of graphene/CuCr composites [J]. Carbon, 2018, 133: 127–139.
 Chu K, Wang F, Li Y, et al. Interface and mechanical/thermal properties of graphene/copper composite with Mo2C nanoparticles grown on graphene [J]. Composites Part A—Applied Science and Manufacturing, 2018: 267–279.
 Saboori A, Pavese M, Badini C, et al. A novel approach to enhance the mechanical strength and electrical and thermal conductivity of Cu-GNP nanocomposites [J]. Metallurgical and Materials Transactions A—Physical Metallurgy and Materials Science, 2018, 49: 333–345.
 Rashad M, Pan F, Asif M, et al. Powder metallurgy of Mg-1%Al-1%Sn alloy reinforced with low content of graphene nanoplatelets (GNPs) [J]. Journal of Industrial and Engineering Chemistry, 2014, 20: 4250–4255.
 Ferrari A C, Meyer J C, Scardaci V, et al. Raman spectrum of graphene and graphene layers [J]. Physical Review Letters, 2006, 97 (18): 187401.
 Chu K, Wang F, Wang X, et al. Interface design of graphene/copper composites by matrix alloying with titanium [J]. Materials & Design, 2018, 144: 290–303.
 Zou Y, Sun Z M, Tada S, et al. Liquid reaction during synthesis of Ti3SiC2 through pulse discharge sintering Ti/Si/TiC mixed powders [J]. Materials Transactions, 2006, 47: 2987–2990.
 Zhou W, Bang S, Kurita H, et al. Interface and interfacial reactions in multi-walled carbon nanotube-reinforced aluminum matrix composites [J]. Carbon, 2016, 96: 919–928.
 Ishida K, Nishizawa T. The C-Co (carbon–cobalt) system [J]. Journal of Phase Equilibria, 1991, 12: 417–424.