Application of Ag-Ceramic Composite Electrodes to Low Firing Piezoelectric Multilayer Ceramic Actuators

Ag-ceramic composite materials were investigated as low-cost internal electrodes for low firing piezoelectric multilayer ceramic actuators. Ag-ceramic pastes were prepared by adding PZT-based ceramic powders to a commercial Ag paste in the range of 0 to 50 wt %. PZT/Ag-PZT multilayered laminates were fabricated using tape casting and fired at temperatures below 950degC. The addition of PZT-based ceramic into the Ag electrode decreased the thermal contraction mismatch over piezoelectric ceramic sheets during sintering, which led to a lower failure rate in device fabrication. The maximum strain of PZT/Ag-PZT multilayered actuators was 9times10^-4 under an electric field of 2.5 MV/m.