Crack‐tip toughness of lead‐free (1−x)(Na1/2Bi1/2)TiO3–xBaTiO3 piezoceramics.

Abstract: Crack opening displacements were evaluated on semi‐elliptical indentation cracks in lead‐free (1−x)(Na1/2Bi1/2)TiO3–xBaTiO3 piezoceramics and a commercially available PZT ceramic. The observed crack‐tip toughness of NBT‐xBT was found to be substantially higher than for PZT. Two evaluations for the crack opening displacement were demonstrated and contrasted: A more elaborate three‐term‐approximation and a pragmatic utilization of the Irwin parabola. [ABSTRACT FROM AUTHOR]