强织构纯钨金属中绝热剪切失稳行为的演化与调控

High-density, high-strength metals with high adiabatic shear sensitivity are always the favored materials for kinetic energy armor-piercing projectiles. The “self-sharpening” effect caused by adiabatic shear failure at the end of the projectile can effectively enhance their penetration capability. In this research, a strong texture is introduced into a pure tungsten sheet by prerolling deformation. Dynamic uniaxial compression tests and microstructure characterization reveal that a strong preferred orientation design is an important way to achieve adiabatic shear instability in refractory heavy metals. The formation and evolution process of adiabatic shear bands (ASB) in strongly textured pure tungsten is systematically analyzed, including the onset and propagation of local shear deformation, thermoplastic accumulation in shear zone to deformation instability, and formation and growth of ASB due to the concentrated thermoplastic flow. This reveals the microscopic mechanisms of anisotropic dynamic shear instability behavior. Moreover, the rolled sheet texture with different crystal orientations was obtained by adjusting the deformation process. The important influence of texture evolution and spatial distribution of grain orientations on the dynamic instability behavior was investigated, and the effectiveness of texture design in regulating mechanical behavior was clarified.