In many instances of mechanical interaction between two materials, the physical contact affects only the outermost surface layer, with little discernable influence on the bulk of the material. The resultant high pressures in these localised regimes can induce surface structural changes such as deformation, phase transformation and amophization. The understanding of these physical phenomena is critical in the study of common 'contact loading' processes such as scratching, grinding, milling, polishing, indentation testing, wear, friction and erosion. This book brings together contributions from experts in their respective subjects, and covers experimental measurement techniques, simulation of pressure indusced phase transformations, amophization and tribology. The first three chapters of the book describe a variety of experimental methods and simulation techniques used in the study of phase transformations. It goes on to consider phase transformations in different materials, namely semiconductors, pseudocrystals and ceramics. The remaining chapters of the book consider pressure-induced amorphization, dynamic loading, ductile regime machining and solid state transformations in tribological processes. The title should be of interest to advanced students and researchers working on any aspect of materials science where mechanical surface interactions are a factor.