Near Net Shape Manufacture of CMC Components

Dimensional stability and reproducibility of the different processing steps for ceramic matrix composites (CMC) is one of the major demands when manufacturing complex structures. Depending on size, shape and required accuracy, the machining of the finished ceramic part can amount to an essential share of the overall production costs. Generally, the lower the total shrinkage during fabrication, the lower the tooling and machining effort. This paper deals with a processing technique which is based on the infiltration of a fluid phase into a porous fibre preform, showing extremely low dimensional changes. The macroscopic shrinkage only occurs in one direction and amounts to less than 7 %. Due to this high dimensional stability during the three step process, complex ceramic matrix composite (CMC) structures can be manufactured cost efficiently.