Strength of VGCF/Al Composites for High Thermal Conductivity

Abstract

In this paper, the evaluation of the strength of the VGCF/Aluminum composites which have high thermal conductivity is reported. VGCF (Vapor Growth Carbon Fiber) is a kind of the Carbon nanotube (CNT) which has very high thermal conductivity as well as CNT. The composites are made by spark plasma sintering. The stress-strain curves of the composites are obtained by the tensile tests and show that the composites have brittle behavior. The brittleness of the composites increases with increase in the volume fraction of VGCF. A numerical simulation based on the micromechanics is conducted to estimate nonlinear behavior in the elastic deformation and plastic deformation of the stress-strain relations of the composites. The theories of Eshelby, Mori-Tanaka, Weibull, and Ramberg-Osgood are employed for the numerical simulation. The simulations give some information of the microstructural change in the composite related to the volume fraction of VGCF.

Correlations between Thermal Conductivity and Inelastic Deformation of Aluminum Based Composites Containing VGCF-CNT Network

“…Figure 7 shows examples of the stress-strain relations of the composites. Figure 7(a) showed stress-strain relations still fracture [22]. Figure 7(b) shows stress-strain relation and the circles and squares show the stress-strain relations of the matrix and the composite containing 30% of VGCF, respectively.…”

“…6 Geometry of test specimens. (mm) (a)still fracture [22] (b)prestrain Fig. 7 Example of stress-strain relations of the composites.…”

“…The authors have fabricated Al matrix composites containing CNT and VGCF using spark plasma sintering (SPS), and showed that the composites had high thermal conductivities and further suggested that the high thermal conductivities arise from VGCF-CNT networks in the composite [20][21][22]. composites.…”

Temperature effect on strength of aluminum based high thermal conductive composites containing VGCF-CNT filler

“…They showed that the composites had high thermal conductivities and further suggested that the high thermal conductivities arise from VGCF-CNT networks in the composite (5,6). In this paper, temperature dependences of both thermal conductivities and strength properties of the composite are investigated.…”

Temperature dependence on thermal and strength properties of aluminum based high thermal conductive composites containing VGCF-CNT fillers

“…There are only a few reports considering the improvement of the thermal conductivity. The authors have fabricated Al matrix composites containing CNT and VGCF using SPS, and showed that the composites had high thermal conductivities and further suggested that the high thermal conductivities arise from VGCF-CNT networks in the composite (Imanishi et al, 2008(Imanishi et al, , 2009Fukuchi et al, 2010). The maximum volume fraction of VGCF of the composites was 60% to obtain the high thermal conductivity.…”