Paper number 708


P.Pujalte, F.J.Narciso-Romero, R.Arpón, F.Coloma, A.Sepúlveda-Escribano, and F.Rodríguez-Reinoso.

Departamento de Química Inorgánica, Universidad de Alicante.
Apdo. 99. E-03080, Alicante (SPAIN)

Summary The presence of residual silicon in RBSC pieces reduces their mechanical properties at temperatures higher than 1300 ºC (mp of Si = 1410ºC). This work presents the study of the substitution of silicon by a refractory silicide (W,MoSi2). The preparation variables have been the carbon source (activated carbon, graphite and coke), the particle size and the experimental conditions used. The best results were obtained when a coke of small particle size was used; in this case, even the preparation of pieces of only SiC-Coke (without using of silicide precursor) with no residual silicon was possible. The use of silicide precursor in the preforms allows the synthesis of SiC-(WMo)Si2 pieces that have no residual silicon. In all cases the mechanical properties of pieces are enhanced when silicon is replaced by silicide.
Keywords reactive infiltration, SiC, WSi2, MoSi2, composites.

Theme : Ceramic Matrix and C/C Composites ; Processing and Forming

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