Self-sharpening ability enhanced by torque gradient in twisted tungsten-fiber-reinforced Cu-Zn matrix composite

The self-sharpening ability is s of great importance for penetrators when penetrating the targets. In this work, we propose a novel and simple structural design of penetrator material based on tungsten-fiber-reinforced Cu-Zn matrix composite. The clusters of tungsten fibers within the matrix are twisted with different amount in the central and edge parts to create a torque gradient. The dynamic compressive behavior of the central and edge parts of the composite is studied under a high strain rate of 2000 s⁻¹. Their yield strength reaches 2180 MPa and 1820 MPa, with a maximum true strain at fracture being 0.2 and 0.05 respectively. The tungsten fibers from the central part fracture by splitting along the direction of the fibers, while the tungsten fibers in the edge part are more easily fractured by shearing. The penetrator made of the tungsten-fiber-reinforced Cu-Zn matrix composite shows a high penetration capability and good “self-sharpening” capacity, which can be attributed to the torque gradient which induces different mechanical responses between the central and edge parts in the composite.