Relation between Chemical, Mechanical, and Electrical Properties of Nb 2 O 5 ‐Modified 95 Mol% PbZrO 3 ‐5 Mol% PbTiO 3

The use of an Nb 2 O 5 ‐modified PZT (containing ∼95 mol% zirconate and ∼5 mol% titanate) in explosively driven electrical power supplies is described. A small but significant number of test specimens exhibit dielectric breakdown during explosive testing. A failure mechanism is proposed in which the electromechanically induced stresses result in fracture. Charged particles released during the fracture process initiate dielectric failure. The fracture toughness and mechanical strength of a given material are about the same for unpoled and poled material, but after pressure depoling, a given material typically exhibits a nominal 50% increase in toughness and strength. Varying the lead concentration from ∼5 at.% deficiency to ∼2 at.% excess results in a degradation in toughness and strength. An optimum niobium concentration is observed at ∼1.8 at.% in terms of mechanical properties and functional performance.