Preparation of PZT Microtubes by Slip Casting on Vermicelli, Followed by In Situ Polymerization

Slip casting of lead zirconate titanate (PZT) slurries of higher solids loading (48.8-51.6 vol%) prepared in a urea-formaldehyde (UF) monomer solution on vermicelli of similar to 1000 mu m diameter has been studied to prepare PZT microtubes with a higher wall thickness (200-960 mu m) in a lower dipping time (0.5-4.0 min) to facilitate faster production and lower failure during drying and vermicelli burnout. Polymerization of the UF monomer by exposing the PZT slurry-coated vermicelli to HCl gas provides good strength and stability to the coating. The dielectric and piezoelectric properties of the microtubes compare well with the properties of PZT-5H ceramic compositions.