Success in the manufacture by the liquid-state route of Al-matrix composites reinforced with 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. A three-step investigation has been conducted to enhance wettability of RHA by two Al-Mg-Si alloys. In the first step, a study on the coating of RHA with Si3N4 by the hybrid system chemical vapor infiltration using Na2SiF6 solid precursor and N-2 and N-2-NH3 as gas precursors, was conducted. The second step consisted of studying the quantitative effect of processing parameters to maximize the amount of Si3N4 deposited into porous silica preforms. In the third stage, a 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 RHA substrates, reagent-grade Si3N4 and Si3N4-coated RHA substrates. (C) 2017 Elsevier B.V. All rights reserved.