Effect of Temperature and Thermal Cycles on PZT Ceramic Performance in Fuel Injector Applications

This thesis presents an experimental analysis of the effect of temperature and thermal cycles on the performance of PZT ceramics in fuel injector applications. Due to the increase in the implementation of piezoceramics in applications such as fuel injection technology, it is imperative to understand how temperature affects piezoceramic performance. In this project, the fundamental piezoelectric properties (d_33, ε_33^T, s_33^E) of bulk PZT samples and high electric-field properties of piezoelectric stack actuators were obtained with respect to temperature and thermal cycles. The results show that increasing temperature will increase the fundamental piezoelectric properties of bulk piezoceramics, capacitance of stack actuators, and the displacement of piezoactuators in the absence of external load. Raising the temperature while applying a constant preload will initially increase piezoactuator displacement, but decrease it at higher temperatures. Temperature had a negative effect on the hysteresis in the displacement-voltage. Additionally, thermal hysteresis decreased significantly in subsequent temperature cycles.MAS