Abstract:

The surface/subsurface damage is generated inevitably in grinding glass-ceramics. In this study, the surface topography, surface/subsurface damage characteristics and material removal mechanism of glass-ceramics ground by diamond wheels with different abrasive sizes of 500#, 1 500#, 2 000# and 5 000# are investigated. The surface/subsurface damage characteristics of glass-ceramics in brittle-mode grinding and ductile-mode grinding respectively are revealed, and a high-efficiency and low-damage ultra-precision grinding process of glass-ceramics by stages using 500# diamond wheel for rough grinding and 5 000# diamond wheel for fine grinding is proposed. The experiment results show that the material is removed in brittle mode when glass-ceramics are ground by 500 #and 1 500# diamond wheels, in both brittle mode and ductile mode when ground by 2 000# diamond wheel, and in ductile mode when ground by 5 000# diamond wheel. In the brittle-mode grinding of glass-ceramics, the surface damage consists of pits, microcracks and deep scratches, and the subsurface damage takes the form of microcracks. But in the ductile mode grinding of glass-ceramics, the surface damage has only micro-scratches, and subsurface damage is the plastic flow of workpiece material closed to the ground surface.

Key words: grinding, material removal mechanism, subsurface damage, surface damage, glass-ceramic