Образцы с пористостью 2–3 и 13%, состоящие из мелкозернистого кварца, диспергированного в серебряной матрице, были подвергнуты ударному сжатию до 28, 33 и 37 ГПа в плоских ампулах сохранения. В образцах с пористостью 2–3% после очистки от серебра наряду с аморфизованным кварцем рентгенографически обнаруживалась кристаллическая фаза высокого давления диоксида кремния, отличная от стишовита и предположительно имеющая моноклинную решетку.

Samples with porosities of 2–3 and 13

A VISAR technique was used to study the structure of the reaction zone in PETN for various initial densities and dispersion of samples. The flow in the pressed charges corresponds to the classical denotation model. In the case of bulk density, the peculiarities corresponding to an explosive combustion model are recorded. In the vicinity of the initial density of 1.7 g/cm 3 , a kink is found on the curve showing detonation velocity versus density, and the shock-wave initiation of PETN above and below the kink point is studied.

The effect of high-temperature shock compression conditions on the degree of transformation of silicon nitride into a cubic γ-modification at pressures of 36 and 50 GPa in planar recovery ampoules is studied. The x-ray Rietveld method is used to determine the quantitative phase composition before and after shock compression. The temperature reached during compression and the residual temperature after unloading are calculated. It is shown that the use of high-temperature shock compression at 36 GPa provides a higher transformation level compared to the classical approach based on the addition of copper powder into the samples.