FRACTURE-BEHAVIOR OF CYCLICALLY LOADED PZT

The fracture behavior of PZT specimens driven at their resonant freque ncy by the application of an ac voltage was investigated and compared with fracture behavior of monotonically loaded PZT. Microcracking was observed in the cyclically loaded specimens; above 150-degrees-C, the microcracks were dispersed in small clusters, while at T less-than-or- equal-to 86-degrees-C, microcracks were generated in a densely populat ed region near the failure site (indentation). Macrocrack growth also demonstrated a temperature dependence, with crack growth occurring at T > 150-degrees-C but not at T less-than-or-equal-to 86-degrees-C.