RECOVERY OF MATERIALS IMPACTED AT HIGH-VELOCITY

Hypervelocity impact can produce unique effects in materials, includin g crystal structures, microstructures, and properties. Examples includ e impact-driven shock waves to synthesize novel materials 1 mm and 1 m um thin shocked to pressures up to 100 GPa (1 Mbar), preferential crys tallographic alignment achieved by taking into account the shape and s ize of powder particles, and high-pressure phase transitions quenched in geological materials. Thin specimens are used to achieve the highes t quench rates. Methods are described which show that the experiments can be performed by precooling or preheating specimens in the range -1 70-degrees to +1000-degrees-C. Calculational results for the quartz ex periments show the importance of computational simulations to determin e the pressure history m the specimen.