A model for prediction of surface roughness in ultrasonic-assisted grinding

Abstract

In recent years, the ultrasonic-assisted grinding (UAG) has found increasingly wider application in the processing of hard brittle materials due to the advantage of improving surface quality compared with common grinding. In the ultrasonic-assisted grinding process, the surface formation mechanism is different from that in the common grinding due to the high-frequency impulses on the workpiece. The nature of the method for common grinding is to solve the intersecting points of any two 2D cutting trajectories by simplifying the abrasive to a point or discretizing the abrasive for multiple points. However, this method does not apply to the ultrasonic-assisted grinding since the cutting trajectory of the grit is a three-dimensional space curve, which may make it difficult to find the intersecting points of any two cutting trajectories. To overcome this problem, a method for predicting the ground surface roughness of the ultrasonic-assisted grinding is developed in this paper. First, the abrasive grain trajectory surface equation as a function of time is established considering the ultrasonic vibration of the workpiece and the shape of the grain. Subsequently, a new simulation model for the surface topography of the grinding process is proposed by dividing up the workpiece into a grid and calculating the minimum value of all grains left at each grid point. Finally, experimental verification is performed, and the influence of the ultrasonic vibration amplitude on surface roughness is discussed. The simulation shows that the proposed method yields the results that are consistent with the experiment, thereby proving the effectiveness of the method.