Improving the Working Surface Condition of Electroplated Cubic Boron Nitride Grinding Quill in Surface Grinding of Inconel 718 by the Assistance of Ultrasonic Vibration

Abstract

The working surface condition of abrasive tool is one of the important issues in grinding process. This article discusses the effects of the ultrasonic vibration on the working surface condition involving chips adhesion and abrasive grains wear during ultrasonic-assisted grinding (UAG) of Inconel 718 with an electroplated cBN grinding quill as the abrasive tool. In this study, scanning electron microscopic (SEM) observations were performed on the quill working surface before and after grinding at different vibration amplitudes, and the SEM images were filtered, extracted, and binarized by using image-pro plus to evaluate the quill working surface condition. The obtained results demonstrated that (1) the wear of grinding quill is dominantly attributed to chips adhesion, grains releasing, and grains fracture; (2) both the percentage of chips adhesion area and the size of chips adhered tend to decrease as the vibration amplitude increases; in contrast, the effect of ultrasonic vibration on the number of chips adhesion is not noticeable; (3) the percentage of the number of grains released/fractured decreases as the vibration amplitude rises, e.g., the percentage in UAG at vibration amplitude of Ap–p = 9.4 μm was decreased by 40% compared to that in conventional grinding (CG); and (4) higher distribution density of effective cutting edges can be achieved under larger vibration amplitude, and the mean area of effective cutting edges in UAG is smaller than that in CG, demonstrating that the ultrasonication enhances the grinding quill sharpness.