Grain-subdivision-dominated microstructure evolution in shear bands at high rates

Shear banding is an important deformation and failure mechanism in metallic systems, especially at high-rate straining. Dynamic recrystallization was often reported to account for the refined microstructure of shear bands but rarely confirmed using direct quantitative measurement. Here, we employ quantitative precession electron diffraction analysis to uncover shear band microstructure in pure titanium. The results reveal that the microstructure is dominated by early stages of grain subdivision process. Dynamic recrystallization is not as prevalent as perceived conventionally. Our results offer key insights into understanding shear banding and highlight the need for quantitative analyses of shear band microstructure. IMPACT STATEMENT A critical quantitative assessment of shear band microstructures is made using precession beam diffraction imaging. Specifically, grain subdivision, as opposed to dynamic recrystallization, drives the shear band microstructure evolution.