Improvement of Aluminum Alloy-Rice Husk Ash Wettability with Surface Modification of Rice-Husk Ash (RHA) by Si3N4 Coating

Description

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 30^o, 72^o and 35^o, 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