Microstructural Aspects of Acoustic Emission Generation in Ceramics

Abstract

The main objective of the studies described in this paper was to determine the conditions under which acoustic emission signals are generated in ceramics prior to failure and to see if these signals have any characteristic features which can be used to determine the microscopic process taking place within the material. In the first section, the techniques used and the materials studied are outlined. Section II then describes the characteristic features of the acoustic emission signals generated during plastic flow of MgO single crystals and accompanying the fracture of polycrystalline ceramics and glass. Following the work of Gatti et al.,¹ the third section describes the establishment of a relationship between the occurrence of an individual acoustic burst and the motion of a slowly growing crack front. The fourth section describes the application of acoustic emission monitoring techniques to the determination of the material parameters appearing in fracture mechanics theories.