Abstract: Success in the manufacture by the liquid-state route of Al-matrix composites reinforced with rice husk-ash (RHA) strongly depends upon its suitable wetting by the aluminum alloys. Since RHA is scarcely wetted by Al alloys, development of appropriate wetting technologies is paramount. Wettability study using the sessile drop method was conducted to elucidate the effect of Si3N4 coating by comparing the wetting behavior by two Al alloys of SiO2 (RHA) substrates, reagent-grade Si3N4 and Si3N4 -coated RHA substrates. Results show that at 1200 oC, in nitrogen atmosphere with high Mg content in alloy, the minimal contact angles obtained for Si3N4, (RHA) SiO2 and Si3N4 -coated RHA substrates are 30o, 72o and 35o, respectively, revealing the beneficial effect of modifying the surface of RHA with Si3N4 coating.
Authors: N. Soltani, A. Bahrami, M.I. Pech-Canul, and L.A. González
Keywords: Silicon Nitride, Rice Husk Ash, Wettability, Aluminum Alloys