Experimental Investigations of Full-Field Deformation Behavior at the Microstructural Length Scale
Samantha Daly (University of Michigan)
Eringen Medal Symposium in honor of G. Ravichandran
Mon 2:40 - 4:00
Salomon 001
Experimental investigations into the quantitative development of full-field deformations at the microstructural length scale have recently been enabled through the use of Digital Image Correlation (DIC) combined with Scanning Electron Microscopy (SEM). However, the nanoscale spatial resolution possible with this approach comes with substantial challenges. First, the application of a suitable small-scale tracking pattern is considerably more challenging than the patterning techniques typically used in optical DIC experiments. Additionally, SEM images suffer from complex spatial and temporal image distortions and can possess high levels of noise, which lead to erroneous displacement values and can hide strain localization. This talk will provide details on these and other challenges associated with this new and powerful experimental approach, and offer strategies to address these challenges. Application of the methodology to the experimental investigation of 99.99% ultrafine-grained pure aluminum, in fields of view ranging from tens to hundreds of microns, will be used to demonstrate the results that can be achieved with its proper use. These multi-scale experiments allow for the quantification of strain localization within grains as well as over larger representative areas of the microstructure. New information on the deformation mechanisms responsible for high strength and ductility in ultrafine-grained Al is obtained by combining the resulting full-field displacement maps with information on the local microstructure from electron backscatter diffraction.