Dislocation and Crack Avalanche Characteristics from Coupled Acoustic Emission Measurements and In Situ Experiments in Metals

In this work, the AE technique is coupled with in-situ micromechanical testing inside a scanning electron microscope (SEM) to study the deformation of Ni microcrystals under monotoic compression and cyclic loading. By continuously recording of the generated AE signals simultaneously with the load-displacement measurements, correlations were found between the AE wave characteristics and different deformation stages. AE analysis in both time and frequency domains was employed to identify different active sources and probe the underlying deformation kinetics which are not discernible from the load-displacement curves solely. In addition, statistics associated with strain bursts in single crystal Ni microcrystal are discussed in detail.