Martensitic phase transformation and pop-in in compression of austenitic steel nanoplates observed in situ by transmission electron microscopy

Abstract

To explore small-scale martensitic phase transformation and its relation to pop-ins observed in stress-strain curve, in situ compression experiments in transmission electron microscope were performed on austenitic steel nanoplates. Diffraction mode test revealed that the transformation indeed occurs at the nanoscale, but the pop-in seems not related with sudden microstructural change. Additional imaging mode test suggests that pop-ins may be caused by rapid formation of slip band and/or shearing-off of the nanoplate.