Sol-gel and microwave processing of PZT materials for sensor and actuator applications

The challenge that many industries relying on electronic ceramics in general and piezoelectric ceramics in particular have encountered is to fabricate reliable and well characterized materials with reproducible properties. The preparation of lead zirconate titanate ceramic used for the fabrication of motion sensors and actuators is closely investigated in this work. The main goal of this investigation is to apply microwave power combined with sol-gel processing of PZT to fabricate ceramic material with good dielectric, piezoelectric and mechanical properties. The sol-gel method is used for the processing of the PZT powder because of its potential for making fine, pure and homogeneous powders. Sol-gel is a chemical method that has the possibility of synthesizing a reproducible material. Microwave energy is used for the calcining of this powder and the sintering of the PZT samples. This process offers the advantages of rapid and uniform heating at lower temperatures and shorter duration than in the conventional case. Furthermore, this method has the potential of producing finer particles as well as denser and mechanically stronger ceramics.;After developing optimum conditions for processing the PZT material, the powder is then used for the fabrication of sensors and actuators. Sol-gel processed PZT samples consistently exhibited lower standard deviation values for the various properties measured when compared to mixed oxide prepared PZT samples. Microwave processing lowered the calcining and sintering temperatures as well, and reduced the processing times dramatically (from 8-9 hrs for sintering to 1-1.5 hrs). Finer grain sizes and higher densities were achieved as compared to the fully conventionally processed powders.;A comparative study of PZT transducers is accomplished to better assess the improvements introduced by these investigations. Two of the actuators were chosen to apply to active vibration control of flexible structures in a laboratory setting. The microwave processed actuator was seen to control the beam faster than the conventionally processed one. This result shows that PZT transducers with excellent performance can be successfully processed using sol-gel powder synthesis and microwave processing.