Frequency effects on fatigue crack growth and crack tip domain-switching behavior in a lead zirconate titanate ceramic

The microstructural origins of the effect of frequency on the electrical fatigue behavior of pre-cracked soft ferroelectric Pb(Zr0.48Ti0.52)O-3 is investigated by means of a high spatial resolution hard X-ray synchrotron source. It is found that there is a strong link between the frequency of the applied bipolar field. domain-switching behavior in terms of ferroelastic reorientation of the domains around the crack tip and the resultant crack growth. The crack growth is accentuated under increased ferroelastic switching and, in particular found to be more pronounced under low-frequency loading. The concept of domain wall viscoelasticity is applied to explain why lower frequencies accelerate crack growth under a bipolar electric field. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.