PROPAGATING OF UNLOADED INDENTATION CRACK IN PZT-5H FERROELECTRIC CERAMICS UNDER SINGLE OR COMBINED MECHANICAL AND ELECTRIC LOADINGS
Propagating of Unloaded Indentation Crack in PZT—5H Ferroelectric Ceramics Under Single or Combined Mechanical and Electric Loadings

Propagating of unloaded indentation crack in a PZT--5H ferroelectric ceramics with various poling states under single or combined action of mechanical and electric loading has been investigated. The results show that the stress intensity factor induced by the residual stress of an unloaded indentation crack is approximately equal to the fracture toughness. The applied stress or/and electric field, positive and negative, can cause propagating of the indentation crack, and the combined effect of mechanical and electric loadings corresponds to applying an efficient stress.