Processing of buffer sheets for sintering of PLZT tapes

A reliable, inexpensive, non-toxic and simple technique was developed for obtaining uniform, thin layers of particles that are particularly useful as anti-sticking and anti-friction coatings during sintering of ceramic tapes or articles. The tape casting technique was used to prepare thin hydroxypropyl methylcellulose sheets containing refractory setter powders. The wetting behavior of aqueous slurries was improved by applying a thin coating of wetting agent on a Mylar carrier and adding small amounts of the wetting to the slurry. The buffer sheets were stacked interlayer with (Pb,La)(Zr,Ti)O3 (PLZT) green tapes and sandwiched between two dense zirconia plates for sintering. This method was shown to effectively prevent sticking and cracking problems associated with the thin ceramic tapes, and to reduce PbO loss from PLZT during sintering. It was also shown that the flatness of the sintered PLZT tapes is dependent on the solids content of the buffer sheets.