Evaluation of thermal conductivity of GNPs-doped B4C/Al-Si composites in terms of interface interaction and electron mobility

Abstract

The examination of the interactions between graphene and other components commonly used in thermal applications is an important approach for the development of materials with high thermal conductivity. For this purpose, graphene-doped boron carbide reinforced AlSi matrix composites were produced using semi-powder and pressure infiltration methods together. These composites were then characterized by SEM, TEM and XRD analysis. Thermal conductivity coefficients of these composites were determined experimentally by Laser Flash method. In order to examine the effect of phonon transfer on the experimental data, the interacting components were simulated, and the interfacial thermal conductivity was calculated with the acoustic mismatch model. Then, theoretical thermal conductivity of composites was calculated by Hasselman-Johnson model and Maxwell's approach. The electrical conductivity of the composites was measured by four-point probe method for electron mobility. As a result, experimental results were found to be slightly lower than the theoretical ones. This was affected by several different factors but the most important one is thought to be related to porosity.