Preheating and precooling in dynamic loading experiments

The CEA Gramat operates several High-Pulsed Power (HPP) drivers and gas guns for dynamic loading experiments, such as quasi-isentropic compression and planar impacts.  The purpose of these experiments is to provide data about the behavior of various materials of interest, such as Hugoniot points or spalling tension.

Usually, these experiments are performed from ambient temperatures. The use of preheating or precooling devices allows us to study the influence of temperature on the material behavior or to explore specific thermodynamic paths from a different starting point.

For both preheating and precooling, we are using devices based on conductive heat transfer to reach stable and homogeneous temperatures in the whole material sample, both with metallic and nonmetallic materials.

A detailed description of the preheating and the precooling devices is presented, as well as results from quasi-isentropic experiments and planar impacts using the devices on study materials, such as aluminum and PMMA. These results highlight the performances of the devices and show the value of  initial temperature conditioning of materials during dynamic loading experiments.