Experimental Investigation on Surface/Subsurface Damage in Rotary Ultrasonic Machining of Glass BK7

Abstract

Experiments were carried out to study the effect of ultrasonic vibration on the surface roughness and subsurface damage (SSD) in rotary ultrasonic machining (RUM) of glass BK7. As a comparison, some conventional grinding (CG) experiments were also performed under the same process parameters with there of the RUM ones. The surface roughness of the RUM/CG samples was measured with a surface profilometer. The SSD of these specimens was assessed and characterized by a measuring microscope with the help of the taper polishing method. Also, the influence of process parameters (cutting depth, feed speed, and spindle speed) on the surface/subsurface quality was discussed. As a result, both the surface roughness and the SSD depth of the RUM/CG specimens were reduced with the increased spindle speed, while increased with the increasing of feed speed and cutting depth of the diamond tool. Compared with the CG process, the introduction of ultrasonic vibration resulted in the higher surface roughness and SSD depth, due to the fact that the max cutting depth of the abrasive in the RUM process increased by an amplitude compared with that in the CG process.