Material removal mechanisms in diamond grinding of granite, part 2: Formation of gloss on granite surface

This is the second in a series of three papers concerned with the removal mechanisms of workpiece materials during the grinding of natural granite with diamond abrasive tools. In Part 1, the morphological features were examined for the granite surfaces and three main mineral compositions during grinding under machining parameters widely ranging from rough sawing to fine grinding. This second part is devoted to studying the formation mechanisms for surface gloss through monitoring the surface roughness and gloss readings on the granite surfaces during vertical spindle grinding with six different diamond mesh sizes. As a comparison, experiments were also conducted for two manually grinding methods. Coupled with an XRD detection of the ground surfaces and a measurement of the temperatures reached at the workpiece-tool contact zone, the gloss reading on a granite surface was found to be closely associated with the value of roughness generated on the granite surface. The gloss reading was found to increase with reducing surface roughness in an exponential curve, which provides an important basis for more efficiently producing better gloss finish on granite surfaces.