Grinding performance of spiral ultrasonic assisted grinding for monocrystal sapphire using vitrified diamond wheel

In machining of monocrystal sapphire, high efficiency and high precision processing are difficult, because monocrystal sapphire is one of hard brittle materials. This study aims to develop an ultrasonic assisted grinding technology for sapphire wafer. In a previous work, spiral ultrasonic assisted grinding (SUAG) was proposed, and an ultrasonic vibrator was designed and produced. The purpose of this paper is to examine the effect of SUAG for sapphire wafer on grinding force, grinding ratio and surface roughness when a vitrified diamond wheel is used. As the results, applying SUAG decreases the normal and tangential grinding forces, and improves the surface roughness. In addition, the wheel wear using a vitrified diamond wheel is improved.