Characteristics of shock-compressed configuration of Ti and Si powder mixtures

摘要

Shock-compression recovery experiments were performed on mixtures of Ti and Si powders of fine, medium, and coarse morphology, and packed at different initial densities, using the Sandia Momma and Poppa Bear fixtures with Baratol explosive. The shock-compressed configuration revealed characteristics typical of either chemically reacted material with fine equiaxed grains, or unreacted material with densely packed Ti and Si particles. The unreacted configuration showed that Ti particles were extensively deformed, irrespective of powder morphology and shock conditions generated by either fixture. In contrast Si particles showed different characteristics depending on the powder morphology, packing density, and shock conditions. The microstructural characteristics of unreacted configuration of Ti and Si powder mixtures were investigated. Mechanistic processes occurring prior to the inception of shock-induced chemical reactions in this system are described.