Ultrasonic-Assisted Dry Creep-Feed Up-Grinding of Superalloy Inconel738LC

Among many machining methods, grinding is the most applicable one for cutting hard-to-cut materials such as superalloys. In this research, effects of longitudinal ultrasonic vibration of workpiece (Inconel738LC) in dry creep-feed up-grinding process were investigated. Mechanism of abrasive grain and workpiece surface interaction and the consequences have been analyzed both analytically and numerically. Then, the results have been compared with experimental findings. Analytical calculations showed that there is a multiple and discontinuous cutting along the contact zone of grinding wheel and the workpiece when longitudinal ultrasonic vibration is used. Two-dimensional finite element modeling in commercial MSC.Superform software, showed the same behavior and results. Grinding forces are one of the major output parameters for evaluations. It was observed that, application of ultrasonic vibration can decrease grinding forces. A practical decrease of up to 27% of vertical grinding forces and up to 22% of horizontal grinding forces has been achieved when using ultrasonic vibration. Finite-Element analysis has shown a reduction of about 40% of grinding forces compared with ordinary grinding. Probable lower risks of thermal damage even for working under dry conditions can be a big advantage of using ultrasonic with grinding.