Experimental study on rotary ultrasonic machining of alumina ceramic: Microstructure analysis and multi-response optimization

Excellent and superior properties of alumina ceramic make it a one of the highly demanded advanced ceramics in the present competitive scenario of manufacturing and industrial applications. However, its effective and economic processing is still a challenge. The present article has targeted to experimentally investigate the influence of several process variables, namely spindle speed, feed rate, coolant pressure, and ultrasonic power on different machining performances, i.e. surface roughness, and chipping thickness. Response surface methodology has been employed to design the experiments. Microstructure of the machined samples has been evaluated and analyzed through scanning electron microscope. This analysis has revealed and confirmed the presence of plastic deformation of work surface that caused the material removal along with the dominated brittle fracture in the processing of alumina ceramic with rotary ultrasonic machining. The multi-response optimization of machining responses has been done by using desirability approach. At the optimized parametric setting, the obtained experimental values for surface roughness and chipping thickness are found to be 0.215 mu m and 0.159 mm, respectively.