Effect of electric current on fracture behavior of GaN piezoelectric semiconductive ceramics

Herein, three-point bending testing of an edge-cracked specimen and finite element analysis were used to determine the fracture toughness of GaN piezoelectric semiconductive ceramics, and the effect of an applied electric current on the fracture properties of the GaN ceramics was investigated. The results indicated that an electric current has a significant effect on the fracture behavior of piezoelectric semiconductive ceramics. Specifically, the application of a relatively low electric current density (1.67 x 10(4) A m(-2)) increased the fracture toughness by 36.8%, while further increases in electric current density reduced the fracture toughness. In addition, the electric current can lead to the ductile fracture of brittle GaN ceramics. Finally, the mechanisms behind these results were systematically analyzed. These findings are useful for designing more reliable GaN electromechanical devices.