| Abstract: | The mechanisms of grinding, a predominantly fracture mechanism in brittle material, and polishing, a predominantly plastic shearing mechanism, appear quite different. However, in a number of cases, it can be shown that the difference between the two mechanisms can be triggered by differences in depth of cut and abrasive size. Results are presented from recent polishing research that tend to support a physico-chemical interaction model involving aqueous diffusion, internal hydrolysis and ion exchange mechanisms that may explain the plastic to brittle transition in silicate materials. The model would seem to have clear implications for both low-scatter polishing and fine machining of silicate materials. |
