Effect of cutting edge truncation on ground surface morphology of hard and brittle materials for optical devices

For the purpose of investigating the effect of cutting edge truncation on ground surface morphology, several kinds of hard and brittle materials used for optical devices, borosilicate glass, glass quartz, crystal quartz and sapphire, are plunge ground with a SD600 metal-bonded grinding wheel, the cutting edges of which are truncated so as to be aligned with the height level of the grinding wheel working surface, after electrocontact discharge truing and dressing. It is found that an improvement of roughness can be obtained for every material investigated, although the degree of roughness improvement depends on the kind of material. Ductile-mode grinding is most likely to be realized in the case of crystal quartz.