Phase transformations and associated microstructural evolution during shock compression of materials

Full text: When materials are subjected to high pressures in shock loading (high velocity impact) experiments they may undergo phase transformations. One such example is zirconium, it transforms from the hexagonal closed packed (hcp) α-phase to the simple hexagonal ω-phase at approximately 7 GPa. Through a combination of post-mortem and in situ techniques, different dynamic drive conditions are utilized to create a set of specimens with various volume fractions of retained high pressure ω-phase and stored plastic work. The mechanical properties of these well-characterized microstructures are subsequently examined. The results indicate that while both plastic deformation and the volume fraction of the high pressure phase play important roles in determining subsequent material properties, the effect of texture evolution due to plastic work may be of critical importance in determining these properties. These findings shed insight into strength of condensed matter under pressure. In this presentation the author (JP) will present the above work as well as briefly introduce the high and hyper velocity impact capabilities at UNSW Canberra able to perform these experiments. (author)