Shock wave compression of the ferroelectric ceramic Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3:: Hugoniot states and constitutive mechanical properties

Although the particular lead zirconate/titanate composition Pb-0.99(Zr0.95Ti0.05)(0.98)Nb0.02O3 (PZT 95/5-2Nb) was identified many years ago as a promising ferroelectric ceramic for use in shock-driven pulsed power supplies, relatively few studies have been performed to characterize its response under shock wave compression. The current study began when strong interest developed in numerically simulating the operation of pulsed power supplies, which required improved models for dynamic material properties. Experiments were conducted on a gas-gun facility to determine Hugoniot states, to examine constitutive mechanical properties during shock propagation, and to investigate shock-driven depoling kinetics. This article summarizes results from the first two of these areas. A baseline material, similar to materials used in previous studies, was examined in detail. Limited experiments were conducted with other materials to investigate the effects of different porous microstructures. Reverse-impact experiments were used to obtain a Hugoniot curve for the baseline material over the stress range of interest, as well as comparative data for the other materials. Wave profiles recorded in transmitted-wave experiments examined the effects of varying shock strength and propagation distance, poling state and orientation, initial density, porous microstructure at a fixed density, and electric field strength. The collective results identify a complex material behavior governed by anomalous compressibility and incomplete phase transformation at low shock amplitudes, and a relatively slow yielding process at high shock amplitudes. Differences in poling state, field strength, and porous microstructure in common-density materials were found to have a small effect on this behavior, but large effects were observed when initial density was varied. Comparisons with similar studies on other ceramic materials show both similarities and differences, and provide insights into possible yielding mechanisms. (C) 2003 American Institute of Physics.