Tape casting of preceramic polymers toward advanced ceramics: A review

In the last 20 years, tape casting, a standard wet‐shaping process to produce thin ceramics, has been applied to manufacture polymer‐derived ceramics ( PDC s). Si‐based polymers, such as polysiloxanes and polysilazanes, also known as preceramic polymers ( PCP s), have been used as precursors/binders replacing conventional raw materials and additives for tape casting process. Thermal processing of PCP s is carried out at lower temperatures in comparison with classical ceramic sintering, particularly of carbides and nitrides. Furthermore, polymeric precursors can be converted into hybrid or composite ceramics, when parts of the polymers remain unreacted. Inert or reactive fillers might be used to reduce both shrinkage and porosity inherently caused by the weight loss occurring during polymer pyrolysis while forming new ceramic phases in the final materials. Alternatively, pore formers might also be added to tailor pore shape, connectivity, and volume (macroporosity). Nevertheless, current equipment and process parameters for tape casting‐based products must be eventually adjusted to fit the characteristics of ceramic precursors. Therefore, the aim of this review is focused on listing and discussing the efforts to produce PDC s using tape casting as a shaping technique. Interactions of system components and effects of treatment, particularly thermal stages, on final microstructure and properties are stressed out. Gaps in the literature concerning processing optimization are pointed out, and suggestions are given for further development of PDC s produced by tape casting.