This monograph describes the mechanical, physical, and chemical phenomena in powders and other heterogeneous materials under high- pressure dynamic deformation. The discussion does not take the traditional approach based on the Hugoniot equations, but views the topic from the point of view of nonlinear phenomena and materials science, emphasizing those aspects of the behavior that are sensitive to structural details. Based on experimental observations, the treatment: - focuses on strongly nonlinear phenomena, such as shock waves, solitons, and localized shear - takes into account effects of materials structure whose size is on the same order as the scale of parameter variation (such as the shock front or shear band thickness) - concentrates on situations not readily found elsewhere in the literature - presents experimental results in a manner that allows others to repeat the experiments or them for validation in analytical or numerical modeling - introduces models that can be verified by experiments Intended for graduate students as well as researchers, the book includes more than ninety problems at the ends of chapters to help the reader develop a deeper understanding of the material.