Dynamic yield and tensile strength of aluminum single crystals at temperatures up to the melting point

This article presents experimental results of the dynamic yield strength an d dynamic tensile strength ("spall strength") of aluminum single crystals a t shock-wave loading as a function of temperature. The load duration was si milar to 40 and similar to 200 ns. The temperature varied from 20 to 650 de greesC which is only by 10 degreesC below the melting temperature. A linear growth of the dynamic yield strength by more than a factor of 4 was observ ed within this temperature range. This is attributed to the phonon drag eff ect on the dislocation motion. High dynamic tensile strength was maintained over the whole temperature range, including the conditions at which meltin g should start in a material under tension. This could be an indication of the existence of superheated states in solid crystals. (C) 2001 American In stitute of Physics.