Thermal Conductivity Changes in Titanium-Graphene Composite upon Annealing

Abstract

KASICHAINULA JAGANNADHAMTi-graphene composite films were prepared on polished Ti substrates by deposition of graphene platelets from suspension followed by deposition of Ti by magnetron sputtering. The films were annealed at different temperatures up to 1073 K (800°C) and different time periods in argon atmosphere. The annealed films were characterized by X-ray diffraction for phase identification, scanning electron microscopy for microstructure, energy-dispersive spectrometry for chemical analysis, atomic force microscopy for surface roughness, and transient thermoreflectance for thermal conductivity and interface thermal conductance. The results showed that the interface between the composite film and Ti substrate remained continuous with the absence of voids. Oxygen concentration in the composite films has increased for higher temperature and time of annealing. TiO 2 and TiC phases are formed only in the film annealed at 1073 K (800°C). The thermal conductivity of the composite film decreased with increasing oxygen concentration. The effective thermal conductance of the film annealed at 1073 K (800°C) was significantly lower. The interface thermal conductance between the composite film and the Ti substrate is also reduced for higher oxygen concentration. Formation of microscopic TiO 2 phase bound by interface boundaries and oxygen incorporation is considered responsible for the lower thermal conductance of the Ti-graphene composite annealed at 1073 K (800°C).

Thermal Conductance of Graphene-Titanium Interface: A Molecular Simulation

“…For example, few-layer graphene (FLG)-reinforced copper composites were fabricated by spark plasma sintering (SPS) with an FLG volume fraction of 2.4 vol% [ 13 ]. The conductance of composites reached 70.4% of international annealed copper standard (IACS) [ 21 , 22 ]. Graphene-Cu nanocomposites foils were synthesized by an electrochemical method showed a high level of hardness, up to 2.2–2.5 GPa, and an elastic modulus of 137 GPa, which were increased by 96% and 30% from those of pure Cu, respectively [ 12 , 23 ].…”

Electrochemical depositing rGO-Ti-rGO heterogeneous substrates with higher thermal conductivity and heat transfer performance compared to pure Ti

“…Titanium has higher melting point (1650 °C), lower density (4.5 g cm −3 ), higher yield strength (140 MPa) and good corrosion resistance [3]. However, the thermal conductivity of Ti and its alloys, 5-21 W (m K) −1 , is lower compared to that of other metals, which limits their further applications [4].…”