Microstructures and mechanical properties of W-Co-Al tungsten heavy alloy prepared by different formation processing

Abstract

High density, high strength and high susceptibility to adiabatic shear banding (ASB) have always been pursued by tungsten heavy alloys (WHAs) for kinetic energy armor-piercing projectiles. To meet the demand, this work reported a novel tungsten heavy alloy with high-density L12 precipitation-strengthened Co9Al9W binder (WCAW). WCAWs were prepared by liquid phase sintering (LPS) and laser ultrashort-time liquid phase sintering (LULPS) respectively. Experimental results show that LULPS technique with large molten pool convection and rapid solidification can produce WCAWs with uniform W distribution, low W-W contiguity and fine W particles. Conversely, W particles in LPS WCAWs were excessively connected and segregated. The uniform distribution, low W-W contiguity and fine W particles enable LULPS WCAW to exhibit better mechanical properties. The ultimate compressive strength of the LULPS WCAWs is ∼2442 MPa, 16.4 % higher than that of the LPS WCAWs. As well, the dynamic yield strength of LULPS WCAWs is high, which is ∼2281 MPa and 37.4 % higher than that of LPS WCAWs.