Processes, cavitation-controlled deformation

Cessna (9) carried out similar experiments as those reported here on several commercial impact thermoplastics over a range of strain rates. His work suggested that the classes of impact plastics studied exhibit a similar transition from volume-conserving to cavitation-controlled deformation processes as deformation rates are increased or temperature decreased. The present work supports those findings, as do the predictions of Bucknall and Drinkwater. Unlike Cessna, in no case did we find evidence of closure of cavities by shear yielding after cavitation. 

In most two-phase ceramics, particle concentrations exceed the rheological threshold discussed above. Therefore, deformation is controlled not by fluid flow, but by direct interactions between the particles that make up the solid. Above the packing threshold, many particles are either in direct contact, or are sufficiently close that particle interactions are important. Processes that occur close to the particle surface dominate the deformation behavior. These processes include solution-precipitation, matrix flow (or matrix percolation) between the particles, and cavitation. 

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