THERMAL ANALYSIS OF FLY ASH REINFORCED AL-GR COMPOSITES

Abstract

Thermal dissipation and management are major problems of electronics and engineering materials that are exposed regularly to heat. Such materials warp or get distorted under thermal stresses due mainly to their material compositions. This work is aimed at studying the effects of reinforcement and thermal conditions on the thermal characteristics of fly ash reinforced Al-Gr composites produced through Conventional Sintering (CS) and Spark plasma sintering (SPS) methods. The Al-Gr matrix was reinforced with four different compositions of fly ash powder (0, 5, 10 and 15 wt.%). Composite samples were characterised through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) for surface morphology, microstructure and phase composition. The composites were also comparatively subjected to Thermo-gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Differential Thermo-gravimetry (DTG), Thermal Conductivity (TC) and Coefficient of Thermal Expansion (CTE) analysis at 20 and 30 °C/min heating rates. The best thermal stability and conductivity were achieved at the heating rate of 30 °C/min, with the 15 wt.% Fly ash reinforcement using the SPS mode. The CTE showed a range of $1.813 \times 10^{-5}$ to $1.89 \times 10^{-5}$ /K for CS and $1.15 \times 10^{-6}$ to $2.099 \times 10^{-6}$ /K for SPS. Better thermal characteristics were achieved with fly ash reinforcement.