Investigation of forced wheel spindle vibration influence on surface formation in grinding of hard materials

Grinding is the primary approach to machining hard materials. During the grinding process, high grinding forces are generated due to the high hardness of the workpiece, forcing the grinding wheel spindle system to vibrate and in turn affecting the ground surface quality. This study investigates the influences of the forced wheel spindle vibration on surface formation in the grinding of hard materials. Models for the forced vibration of the aerostatic bearing spindle and surface formation in the grinding process are proposed, combined with grinding experiments to analyze the effects of the vibration on the surface waviness and roughness. The analysis shows that the tilting spindle vibration plays an important role in the formation of a periodic wavy ground surface. The dynamic characteristics of the tilting vibration are studied, and twin natural frequencies for tilting vibration modes are found through simulation and experimental analysis. Besides, the increasing amplitude of the vibration at the fundamental frequency enhances the surface waviness but hardly affects the surface roughness. However, harmonic vibrations have great influences on both waviness and roughness. This work is meaningful and could provide practical guidance for improving surface quality through optimizing the grinding process.