Study on improving “self-sharpening” capacity of W-Cu-Zn alloy by the pressureless infiltration method

In order to improve the “self-sharpening” capacity of the tungsten heavy alloy (WHA) for kinetic energy projectile application, the WHAs should have not only high strength but also proper critical shear failure strain. For the purpose of fabricating the WHAs with high strength and proper critical shear failure strain, in the present study, the WHA composed of 80W-14Cu-6Zn was prepared by W skeleton infiltrated of Cu-Zn alloy. The microstructure and mechanical properties were systematically investigated. Microstructure analysis shows that W particles are connected to form W skeleton, and the interstice of W skeleton is filled up with α phase Cu-Zn alloy which has lamellar feature resulting from spinodal decomposition during the preparation process. Due to the solid solution strengthening effect of Zn in the matrix, the static yield strength and the dynamic yield strength of the 80W-14Cu-6Zn alloy are respectively enhanced by 200 MPa and 400 MPa compared with those of the 80W-20Cu alloy. Moreover, due to the proper ductility of the Cu-Zn alloy matrix, under the uniaxial dynamic compression test, the critical shear failure strain of the 80W-14Cu-6Zn alloy is effectively controlled within 0.2-0.4, which is beneficial to promote “self-sharpening” effect during the penetration process for kinetic energy projectile application. Additionally, the failure mechanism of the 80W-14Cu-6Zn alloy under dynamic compression was discussed. The ballistic impact experiment has proved that the 80W-14Cu-6Zn alloy exhibits remarkable “self-sharpening” capacity.