Elastic moduli and dynamic yield strength of metals near the melting temperature

Under conditions of shock-wave experiments at elevated temperatures, there was observed an anomalous growth of the Hugoniot elastic limit (HEL) in aluminum and magnesium with increasing temperature. In aluminum, the HEL increased by a factor of four as the temperature approached the melting point. For magnesium, the dependence of the HEL on the temperature achieved a maximum at 857 K. Both the thermal equation of state and the temperature dependence of the elastic moduli were considered. It was found that the Poisson’s ratio of aluminum is practically constant up to 700 K, and then sharply grows. The analysis confirmed that the dynamic yield strength of aluminum increases by a factor of two as the temperature approaches the melting point, and for magnesium it achieved a maximum at 857 K.