Abstract: Al/B4C/Rice husk ash (RHA) composites were fabricated by using one step pressureless infiltration. The quantitative effect of processing parameters (Temperature, time, particle size, preform porosity, RHA crystallinity and chemical composition of alloy) on electrical conductivity and thermal diffusivity of all fabricated composites were investigated. Using Taguchi method, it was found that at the levels studied for pressureless infiltration of B4C/RHA, the parameter that affects the electrical resistivity of graded composites most significantly is the initial preform porosity, with a contribution percentage of 31 %. Verification tests conducted using the established optimum parameters show a good agreement with the projected values of electrical resistivity. The results also show that using low content magnesium alloys (9 wt.% Mg) and low content of silica (5 wt.%) in composite can yield a composite with higher thermal diffusivity.
Authors: A. Bahrami, N. Soltani, S. Soltani, M.I. Pech-Canul, C.A. Gutiérrez, L.A. González, A. Möller, J. Tapp, and A. Gurlo
Keywords: Rice Husk Ash; Electrical Resistivity; Thermal Diffusivity