Structure of Shock Waves and Inelasticity in Shock-Compressed Cemented Tungsten Carbides

Abstract

In the present study, shock wave experiments are conducted on General Carbide cemented tungsten carbide with 3.7 wt.% cobalt binder to determine its shock-induced compression behavior up to 100 GPa. The measured wave profiles indicate the cemented tungsten carbide undergoes elastic-plastic deformation during shock compression. 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 substantial post-yield hardening, and finally a rise to the peak shocked Hugoniot state. The results of the experiments are used to determine the HEL, the shock velocity (Us) vs. particle velocity (up) Hugoniot relation, and the longitudinal stress (σx) vs. specific volume (V) curve for the samples. The HEL of the material was determined to lie between 4.41 and 4.58 GPa. The Us − up relation was determined to be Us = 4.97 + 1.457up for particle velocities greater than 0.75 km/s. The measured plastic shock velocities for particle velocities less than 0.7 km/s were found to be larger than those predicted using the linear Us − up Hugoniot relationship, indicating the cemented WC samples to preserve substantial shear strength in the post-yield deformation region. No phase transformation was observed up to 100 GPa.