Sintering Behavior of Hard-Soft PZT-Type Composite Ceramics

Abstract

Functionally graded materials represent a new class of composite type materials characterized by a continuous variation of properties through the thickness direction. Due to this they found numerous applications in aerospace, automobile, biomedical or nuclear industries. Bilayered structures made from typically hard and typically soft PZT type materials as well as plain hard and soft and intimately mixed hard and soft samples were prepared by green pressed powders followed by sintering at different temperatures between 1000 and 1300°C. The dielectric and piezoelectric properties of sintered compacts were determined in relation with the nature of the interdiffusion layer involved. Electron microscopy as well as X-Ray diffractometry was used to get an insight into the interfacial diffusion process. The composition and the width of the interdiffusion layer depend on temperature. The mechanism of the interdiffusion layer and materials properties were discussed in terms of the ionic diffusion coefficients and activation energies of the species which take place into the diffusion process.

Keywords:

• PZT
• hard-soft composites
• sintering
• interdiffusion
• piezoelectric properties

Acknowledgments

The authors thank to the NATIONAL CERES PROGRAM, Project no. 2-CEx-06-11-42/2006, for partially financing the researches and the participation at the International Conference ECAPD-8, September, Metz, France, 2006, where the scientific results were disseminated.