This review provides an analysis of the state of the art in the emerging research
area of high-pressure surface science of silicon. Phase transformations and amorphization
that occur in silicon under contact loading, such as indentation with hard indenters,
scratching or machining, will be described. Contact loading is one of the most common
mechanical impacts that materials can experience during processing or use. Examples are
dicing, slicing, grinding, polishing and other machining operations. This kind of loading may
be accommodated by such competing processes as dislocation-induced plasticity, microfracture,
mechanochemical interactions with the environment and/or counterbody, and changes in the
material's structure (phase transformations). The former ones have been studied by mechanical
engineers and tribologists, but the processes of phase transformations at the sharp contact
have only been investigated for a very few materials (silicon is one of them) and further
research is necessary. One of the reasons for the lack of information may be the fact that
the problem is at the interface between at least three scientific fields, that is, materials
science, mechanics, and solid state physics. Thus, an interdisciplinary approach is required
to solve this problem and understand how and why a hydrostatic or shear stress in the
two-body contact can drive phase transformations in materials.
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