Mirror surface grinding of sapphire by coarse grain size diamond wheels

Abstract

This paper discusses the grinding of sapphire for mirror surfaces by coarse grain size diamond wheels. Sapphire is a hard-to-machine material because it has excellent mechanical properties and indentation hardness. Since it is effective for hard materials to use metal-bonded diamond wheels, the authors had two experiments to investigate mirror surface grinding by coarse grain size diamond wheels. The 1st experiment was investigating appropriate grinding conditions, and the 2nd experiment was investigating protrusion height of abrasive grains. Although the conventional methods could not acquire mirror surface, the results of the experiments show that mirror surface (Ra: 5 nm <) were obtained by the #270 and #325 mesh size wheels. These results indicate the possibility of decreasing grinding processes by coarse grain size diamond wheels.

Investigation into the anisotropy of cross-grinding surface quality in C- and M-planes of sapphire

“…6,7 Early studies about sapphire grinding were mainly based on the performance of diamond wheels, including the grain size, concentration, bond material, etc. [8][9][10] More recently, ultrasonic vibration assisted grinding (UVAG) of sapphire was conducted to improve the grinding wheel state and promote the ductile material removal. [11][12][13] Besides, Wu et al 14 investigated the chemical mechanical grinding (CMG) of sapphire by a new chromium oxide (Cr 2 O 3 ) grinding wheel, and a high material removal rate and better surface quality were obtained.…”