An experimental investigation of sapphire grinding by porous and vitrified M0.5/1.5 diamond grinding wheel

Abstract

Monocrystalline sapphire is known to be difficult to machine. Sapphire generally is machined with chemical mechanical polishing technology. However, low material removal rate (MRR) in machining gives rise to several limitations on mass manufacture of sapphire. Fixed ultrafine abrasive grinding is a promising technology for precision grinding of sapphire substrate and offers the possibility of improving manufacture efficiency. In this study, a novel porous and vitrified M0.5/1.5 diamond grinding wheel and preparation equipment are fabricated in an innovative way to precisely grinding sapphire. The experimental results demonstrate the recommended technological parameters for the grinding wheel, speed for which is below 1200 rpm, pressure below 15 N, and sapphire spindle speed lower than 30 rpm. Meanwhile, the removal mechanism of sapphire under the recommended technological parameters is in ductile grinding mode. Besides, in this study, the MRR of sapphire is 10.2 µm / h when the recommended technological parameters are adopted, the Sa of the sapphire after grinding is 0.03 µm and no depth of subface damage layer is observed.