Drilling of Engineering Ceramics using Combination of Ultrasonic Vibrations and Diamond Slurry

Engineering ceramics due to high-strength-to-weight ratio, wear and corrosion resistance, and high strength temperatures, in the industries especially in aerospace, automobile, electronics and computers are used widely. In attention to the  increasingly usage process of these material, applying of conventional machining methods  for producing  machined into complex and desired shapes or making hole with  high production ratio and adequate accuracy, are not suitable and it commonly has not enough output. Ultrasonic machining is a modern mechanical machining method that is appropriate to create holes in hard and brittle materials by means of an ultrasonically vibrating properly-shaped tool that exciting vertically on the workpiece and abrasive slurry.  In this article modal analysis is used to choose the best shape for wave amplitude magnification and concentration. A desktop CNC milling machine is used to create feed motion control on ultrasonic head on a ceramic sample.  Effects of input factors: power, abrasive grit size, slurry concentration and feed rate are analyzed by Taguchi method on the material removal rate (MRR), tool wear rate (TWR) and hole over size (HOS). The results imply that among input parameters, power has the most effect on MRR, also grit size and feed rate have the most effects on TWR and HOS.