Reactive Melt Infiltration Processing of Biomorphic Si–Mo–C Ceramics from Wood

Abstract

Different kinds of natural wood specimens (beech, pine, and rattan) were converted to biomorphic, microcellular Si–Mo–C ceramics by reactive melt infiltration processing. During processing at 1500°C under vacuum the carbon of the pyrolyzed native preforms reacted with Si of the infiltrating Si–Mo eutectic melt (90.4 wt% Si). The resulting materials have fractional densities of >90%, and contained silicon carbide (SiC), MoSi2, in addition to unreacted Si and carbon. The residual carbon remains covered by SiC. The conversion process retains the microcellular morphology of the parent wood tissue. Depending on the initial morphology of the different kinds of wood, reactive melt infiltration processing of Si–Mo–C ceramics can be used to manufacture light weight materials with low density but adequate strength for wide ranging applications where anisotropic behavior is required.