Shock compression and spalling of cobalt at normal and elevated temperatures

Searching for a possibility of registering polymorphic transformations in cobalt under rapid extension, we measured free-surface velocity profiles of high-purity cobalt samples subjected to shock-wave loading at temperatures of 20–400$^\circ$C. In this temperature range, the spalling strength of cobalt at rates of its extension of 10$^5$ – 10$^6$ sec$^{-1}$ was measured, and the relaxation properties of this material under compression in the shock-wave front were estimated. In the experiments, we failed to observe expected wave-profile anomalies due to possible high-temperature polymorphic transformation of cobalt under extension. Most probably, the volume change due to transformation is too small to exert notable influence on the wave-profile structure.