Ceramics are difficult to cast and are not suitable for forging.
However, they can be sintered; the part is made from powder compressed into the shape of the final part, then taken to a high temperature (below melting point) where agitation from the vibrating molecules fuse themselves together. (Ceramic Pottery is a sintering process)
The biggest problem is crack propagation. Unlike metals that get stronger under cyclic load. Ceramics always have small cracks. These open up under cyclic loading and component life is usually dominated by the time it takes for the crack to become long enough to fail the component. Static parts are quite common; guide vanes for gas turbine engines for example, but moving or rotating parts are still a challenge, with some successful implementations.
Hi Paul, I think Mathada question is whether we can use foundry casting instead of machining for making certain engine components.
Of course we can use coating by ceramics (e.g. using plasma spraying) but to do conventional casting of ceramics there is no way to do it.
The most common way to make components completely made out of ceramics is by powder metallurgy (compaction and sintering). Alternatively for certain types of ceramics we can use slip casting technique.