Tool wear monitoring for micro-end grinding of ceramic materials

As grinding process usually is a final step of a machining procedure, excessive grinding tool wear could deteriorate both workpiece surface quality and its dimensional accuracy. This becomes more severe in the case of microgrinding than in conventional grinding because microgrinding wheels are more sensitive to tool wear. An effective tool wear monitoring technique is, therefore, crucial for maintaining consistent machining quality and high efficiency in microgrinding. In this paper, the influence of tool wear and tool stiffness on microgrinding process signals such as grinding force, grinding system vibration, acoustic emission signal and spindle load, are analyzed during end grinding of ceramic materials. To indicate the actual wear status of a microgrinding wheel, this study proposed a new monitoring parameter by fusing grinding force and system vibration signals, based on the concept of varying cutting stiffness. This new monitoring parameter is then experimentally tested in microgrinding a series of ceramic miniature features with consistent and inconsistent geometry.