Role of complex microstructures on high rate loading response

Generally, deformation mode by adiabatic shear is associated with applied high deformation rates. In this context, some clarifications are invoked on at least two levels. First, on the level of critical events regarding the competitive nature between the soft localized shear and micro-cracking onset. Second, on the essential distinction between remote strain rate in contrast to local one. As such, localized behavior might depend on the discrete crystal plasticity, microstructure and on deformation mechanisms. The current study in iron base, tungsten and uranium alloys was aimed toward two fold objectives. (i) To demonstrate the role of complex microstructures on strain rate response. (ii) To emphasize the loading state effects. The study was mainly conducted by utilizing uni-axial compressive specimens in strain-rate values up to 100 sec^-1 at temperature range between 77 to 296 K. Besides this, fatigue tests were performed with emphasis on frequency effects up to 150 Hz. Fine-scale features observations using TEM and SEM were supplemented. The study confirmed remarkable propensity for shear localization in all the investigated materials. Finally, the implications of the present findings are analyzed and further discussed.