A combined study of surface roughness in polycrystalline aluminium during uniaxial deformation using laser-induced photoemission and confocal microscopy

Abstract

A new technique integrating measurements obtained by photo-stimulated electron (PSE) emission and scanning laser confocal microscopy (SLCM) has been developed to characterize the deformation of commercially pure aluminium in uniaxial plastic strain. Real time, in situ PSE signals provide details about the evolution and propagation rates of surface events during the deformation process. High-resolution SLCM measurements yield details describing the relative magnitude and spatial distribution of the surface features. During homogeneous deformation, uniform generation of surface area produces a monotonic increase in PSE intensity whereas necking induces a saturation condition. Analysis of the surface area created by the deformation revealed that the rate of generation correlates well with the PSE intensity. The consistencies in the data acquired with these two techniques signify that they yield complementary information and that the combination provides essential details about the deformation process in a material with low hardness such as an aluminium alloy.

Acknowledgements

This work was supported by Department of Energy under Grant Number DE-FG03-02ER45988. The authors (MRS) would like to thank Stanley A. Janet of the NIST Information Technology Laboratory for his contributions to the software used to convert the topographic data contained in the TIFF images into the numeric matrix format. In addition, the authors (MC) would like to acknowledge AAPIFSA of Washington State University for providing travel funds to NIST.