C/C-SiC Materials Based on Filament Wound CFRP Preforms

Kurzfassung

At DLR, CMC materials and structures based on the LSI process have been developed since the late 1980`s. In the first step of the LSI process, a CFRP preform is made using common technologies like resin transfer moulding (RTM), autoclave technique or warm pressing. Subsequently, the CFRP preform is pyrolysed and infiltrated by molten silicon. Thereby, the silicon reacts with carbon, forming a SiC matrix, leading to the final C/C-SiC material. Up to now, carbon fibre 2D woven fabrics have been used for the manufacture of thin walled, C/C-SiC structures like nose caps for thermal protection systems of spacecraft. However, for highly loaded, lightweight structures like nozzles or combustion chambers, the use of 2D woven fabrics is critical, due to the inadequate drapability and the resulting, limited strength. Therefore, CFRP-preforms based on filament winding, a well known process for the industrial production of tubular structures, have been adapted to the LSI process. Thereby, the winding angle of the fibre was varied systematically. In the resulting C/C-SiC material a strong influence of the fibre orientation to the mechanical properties was observed. In this presentation the manufacturing of tubular C/C-SiC structures via filament winding is described in detail and first results regarding microstructure and mechanical behaviour are given.