Carbon Fibre Reinforced SiC Materials Based on Melt Infiltration

Abstract

For the manufacture of carbon fibre reinforced SiC materials, three different processes are used in principle: Chemical Vapour Infiltration (CVI), Liquid Polymer Infiltration (LPI), also called Polymer Infiltration and Pyrolysis (PIP) as well as Melt Infiltration or Liquid Silicon Infiltration (MI / LSI). Depending on the differ-ent methods for building up the SiC-matrix and embedding the carbon fibres in the brittle ceramic matrix, the resulting C/SiC and C/C-SiC materials vary significantly in their properties as well as in their manufacturing costs. The advantages of the MI processes are their short manufacturing times and the use of low cost raw materials, leading to the most cost efficient Ceramic Matrix Composites (CMC), compared to materials de-rived from CVI and PIP. In combination with their unique thermal and mechanical properties, MI based CMC`s opened up a wide field of new applications beyond aerospace. This presentation gives an overview of the manufacturing processes and resulting properties of C-fibre rein-forced SiC materials. Typical applications of C/C-SiC or C/SiC materials based on MI processes, like friction materials, hot structures for solid propellant rocket motors and temperature stable structures for optical tele-communication systems are presented.