Green body formation processes

In this chapter, we have described the colloid chemistiy of ceramic powders in suspension. Colloid stability is manipulated by electrostatic and steric means. The ramifications on processing have been discussed with emphasis on single-phase ceramic suspensions with a distribution of particle sizes and composites and their problems of component segregation due to density and particle size and shape. The next chapter will discuss the rheology of Uie ceramic suspensions and the mechanical behavior of dry ceramic powders to prepare the ground for ceramic green body formation. The rheology of ceramic suspensions depends on their colloidal properties. 

The second set of synthesis steps shown in Fig. 9.2 concerns the preparation of the green body for the C3 formation. Steps 5-8 are related to generating a flat or curved sheet from the carbon fiber and the precursor of the binder phase. This process can be complicated because the final part made from C3 cannot be changed in its form nor can it be interconnected to another C3 part by reasonably affordable techniques suitable for mass production. The quality of the final product is here decided by the homogeneity of the material distribution and the exact shaping. 

Another important area in dielectric processing is the formation of dense, sintered bodies and the formation of thin layers (<25 pm) in the green (unfired) state for the fabrication of multilayer structures. Densification and microstruc-tural development during ceramic processing are influenced by the characteris-... 

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