Sub-microsecond yield and tensile strengths of metals and alloys at elevated temperatures

The shock-wave tests have been carried out for Armco-iron, aluminum and Al-6%Mg alloy, and titanium of different purity at temperatures up to 600degreesC. The dynamic yield stresses are practically athermal for Al-6%Mg alloy and titanium of commercial purity, decrease for Armco-iron and anomalously increase for titanium of high purity with increasing the temperature. The different behaviors of metals and alloys are treated in terms of relationship between phonon drag of motion of dislocations and the drag forces created by obstacles. The spall strength slightly decreases with increasing the temperature and, for polycrystalline aluminum and aluminum alloy, precipitously drops as temperature approaches the melting point. The waveforms for pure titanium indicate irreversible polymorphic transformations at normal and elevated temperatures.