Liquid Silicon Infiltration is an important process in the manufacture of modern ceramic matrix carbon fiber reinforced composites. These composites have superior material properties, such as high thermal stability, high thermal conductivity, low density and high abrasion resistance.
Due to their properties, C/C – SiC composites are therefore the material of choice in highly oxidizing atmospheres and very high temperatures. The material is used, for example, in jet vanes for missile rockets, brake pads for sport cars, bullet proof vests and nose caps for spacecrafts (reentry into earth atmosphere).
One major manufacturing process of these compounds is Liquid Silicon Infiltration, more accurately the liquid silicon infiltration (LSI) of porous C/C. Compared to other processes like chemical vapor infiltration, LSI is a cost efficient and quick manufacturing process, which may be carried out in Carbolite Gero's HTBL GR vacuum furnace.
During heat treatment in the furnace, silicon is melted on top of the porous C/C material and diffuses into the pores of the material. This results in the reaction of the carbon matrix with silicon, which forms SiC and yields a dense material with C/C segments separated from each other by SiC.
The all-around accessibility of the HTBL furnace is very advantageous for this application. The automatic software control makes unattended operation possible and ensures a proper data logging.
Deux fours HTBL 80 GR/22-1G pendant l'installation sur le site du client. Un HTBL est utilisé pour le process de pyrolyse, l'autre HTBL fonctionne pour la procédure de siliconisation .
Une unité de pompage roots est utilisée pour l'évacuation jusqu'à la gamme de vide fin. Une pompe spéciale à huile fraîche est utilisée pour effectuer le processus de déliantage en pression partielle. L'unité de pompage est montée sur un support indépendant.
Vannes en position originale avant siliconage : Vannes perpendiculaires aux tiges de graphite. Tiges de graphite parallèles les unes aux autres. Le même creuset après siliconage est montré sur la photo suivante.