Quantifying the progression of dynamic recrystallization in severe shear deformation at high strain rates

This paper examines the onset and progression of dynamic recrystallization (DRX) phenomena under shear deformation conditions characterized by strains >1 and strain rates >102/s by purposing large strain machining (LSM) as a test of microstructure response. To accomplish this, samples are created using LSM while characterizing the deformation using digital image correlation and infrared thermography. Microstructural consequences resulting from the characterized thermomechanical conditions are examined using electron backscattered diffraction. The progression of DRX is measured by identifying the threshold of grain orientation spread demarcating the onset of recrystallization and utilizing this threshold to segregate the microstructure and quantify the extent of DRX. A model for the onset of DRX as a function of thermomechanics of deformation is presented. This characterization can help understand surface microstructures resulting from shear-based manufacturing processes, such as turning, milling, shaping, etc., that are created under analogous thermomechanical conditions.