Plastic deformation of microsamples: Intermittent dislocation avalanches and their acoustic emission

Abstract

On the micrometer scale, deformation properties of metals change profoundly: the smooth and continuous behavior of bulk materials is often replaced by jerky flow due to random strain bursts of various sizes. The reason for this behavior is the complex intermittent redistribution of lattice dislocations due to external loading. This process also leads to the formation of the uneven step-like surface upon deformation. Our highly sensitive micromechanical platform can detect the strain bursts caused by dislocation avalanches in three different ways: (i) by stress and strain measurements using a capacitive displacement sensor measuring the elongation of a spring, (ii) by detection of the emitted acoustic signal using a sensitive piezoelectric transducer and (iii) by visual images using the electron beam of the SEM. In my presentation, I will present two of our recent results obtained with the help of this toolbox. Please click Download on the upper right corner to see the full abstract

    Similar works