Lapping is a method of ultra-fine grinding using loose abrasives, with the abrasive grains acting as cutting edges. Kinematically, lapping is characterised by a variety of relative movements of the abrasive grains and the workpiece surface.
There are three types of lapping, depending on the type of tool:
- lapping with laps – the abrasive grains (alumina, carborundum, boron carbide or diamond dust) are partially embedded in the lap surface (which acts as the shank part of the tool) and participate in the machining of the workpiece with their protruding edges. The lap material, which holds the grains in their current position, acts as a binder on the grinding wheel. The removal of material particles in this case is purely mechanical.
- vibration lapping – the workpieces are placed in an abrasive mixture and, together with it, are subjected to shocks of adjustable vibration frequency, amplitude and direction.
- drum lapping – the workpieces are placed in closed rotating tanks (drums), partially filled with an abrasive mixture, and the whole drum is then subjected to a rotary motion.