Shock response of cobalt-based cemented tungsten carbides at pressures up to 100 GPa.

In the present study, shock wave experiments are conducted on General Carbide cemented tungsten carbides with 3.7 wt.% and 6.0 wt.% cobalt binder to determine their shock compression response up to 100 GPa. A three-stage particle velocity profile is observed in the experiments -- an initial elastic-rise to the Hugoniot elastic limit (HEL), an elastic-plastic ramp indicating post-yield hardening, and finally a rise to the peak shocked Hugoniot state. The results of the experiments are used to determine the HEL, shock velocity (U_s) vs. particle velocity (u_p) Hugoniot relationship, and the longitudinal stress vs. specific volume Hugoniot relationship for the two samples. The HEL for the WC 3.7wt% Co and WC 6.0wt% Co samples was determined to be∼4.45 GPa and 3.72 GPa, respectively. The U_s – u_p relation was determined to be U_s=4.97(0.006)+1. 446 (0.018) u_p for WC 3.7 wt.% Co and U_s=4.93(0.006)+1. 454(0.017)u_p for the WC 6.0 wt.% Co sample at peak particle velocities>0.75 km/s. For both WC grades, in the particle velocity regime less than ∼ 0.75 km/s, the measured shock wave velocities were found to be larger than those predicted by the linear U_s−u_p Hugoniot relationship, indicating the two WC samples to preserve substantial strength in the post-yield deformation regime. Both WC grades show a catastrophic drop in shear stress carrying capacity when shocked to longitudinal stresses greater than∼70 GPa. [ABSTRACT FROM AUTHOR]