Influence of processing parameters on microstructure and ferroelectric properties of PZT-coated SiC fibers

SiC fibers have been coated with coprecipitated PZT powders by electrophoretic deposition. Zr and Ti hydroxides, respectively, and Pb carbonate are precipitated from homogenous nitrate solutions at pH values between 5 and 7. The platinum-coated SiC fibers were electrophoretically coated with these coprecipitated PZT powders after calcination and milling. The coated fibers were sintered at temperatures of about 1170 °C. With the low solid yield of the suspension and the low layer thickness compared to the sparking distance an almost constant growth rate of the layer is observed during electrophoretic deposition of the PZT powders at a coating voltage of 50 V and a coating time of up to 180 s. Remanence and coercive field strength characteristics of the fibers sintered at 1170 °C increase with increasing sintering time and density and range between 11 and 25 μC/cm2, respectively, between 12 and 22 kV/cm in good correspondence with literature values for pure PZT fibers.