Ultrasonic is an advanced technology in different manufacturing processes. One of the progressive applications of this technology is in ultrasonic assisted machining (UAM), such as drilling.However, this process suffers from the limitations coming from the rotation incapability of the transducers.By improving the system thorough providing rotational capability,this advanced drilling technology can be used for any industrial part, regardless of its size and the location of the hole, and also higher finishing quality can be achieved.In this thesis, an innovative mechanism is designed to utilize ultrasonic transducer to axially vibrate the drilling tool, while it is simultaneously rotating – like a conventional drilling process.Slippery rings and graphitic brushes were employed to provide electrical connection between the ultrasonic power supply and the rotating piezoelectric transducer. The transducer was shielded into a Teflon cylinder for safety reasons. Copper rings were installed on the Teflon cylinder, and were connected to the transducer by means of wires passing through the Teflon. Once the setup was prepared, statistical experimental studies were carried out. Design and analysis of the experiments were performed by MINITAB – one the strongest software in the field of statistical analysis. Spindle speed, feed rate, and the vibration amplitude were taken as input factors, while surface roughness, circularity, and cylindericity were studied as output parameters. MINITAB specified experiment scenarios, based on input factors and the chosen analytical method. Finally, by analyzing the variance and the regression of the results, the software specified optimal conditions of the process. Experimental results of rotary ultrasonic assisted drilling (R UAD )showed higher machining quality in comparison with conventional drilling. Also, the generated chips were thinner and discontinuous. Generated contours and surfaces, and also statistical analysis of the experimental results showed that the input factors had all significant effect on the output parameters. It can be due to the fact that the friction mechanism changes to stick-slip friction, and lower energy is dissipated. . This can be justified by the fact that the chips were much smaller, and this facilitates the removal of the chips from the cutting zone. All these mentioned advantages, lead to the reduction of the friction between the tool and the work piece, reduction of the machining temperature, and consequently to the increase in the lifetime of the tool. The preliminary obtained results of the current research were quite encouraging, lending to a rationale to extend the technology to manufacture a general tool for RUAD, in particular for drilling of the materials with low machining properties, such as super alloys. Keywords : Drilling; Rotary ultrasonic drilling; Hole quality; Statistical Analysis
