Paper number 708

SYNTHESIS OF A CERAMIC COMPOSITE MATERIAL: SIC-(W,MO)SI2

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.