PZT BASED PIEZOELECTRIC CERAMICS WITH ENHANCED FRACTURE-TOUGHNESS

The microstructures and phase constitution of Bi4Ti3O12 toughened PZT ceramics were characterized together with the fracture toughness and p iezoelectric properties. By the present approach, the fracture toughne ss of PZT ceramics was significantly enhanced (K-IC = 2.8 MPa m(1/2)) without dramatic degradation of the piezoelectric performance. The dis cussion on phase equilibrium concluded that some more stable bismuth l ayer compounds such as PbBi4Ti4O15 should be adopted as a secondary ph ase to toughen PZT piezoelectric ceramics, and then the subsequent neg ative effects on piezoelectric performance might be suppressed. (C) 19 98 Elsevier Science B.V. All rights reserved.