Experimental investigation on performance of touch-dressed single-layer brazed cBN wheels

Electroplated single-layer grinding wheels, in spite of offering unique useful features like geometrical flexibility, large chip accommodation volume in the inter-grit space, etc., produce high transverse surface roughness on the ground surface of the workpiece. Non-participation of all the superabrasive particles (grits) attributes to this limiting factor. Moreover, in plunge grinding the situation is the worst to deal with. This work is an attempt to reduce the same to an acceptable magnitude so that post-grinding finishing operations can be executed effectively. However, this procedure has been implemented on indigenously developed brazed-type single-layer cBN wheels. This class of grinding wheel has been found superior to its galvanically bonded counterpart in the view of larger grit protrusion and flexibility to print any pattern of grit distribution. In this investigation, brazed cBN wheels with different grit distribution patterns have been conditioned by touch-dressing method so that grit tips get micro-conditioned and allow the underlying grits to participate and consequently increase the quality of finish. The outcome of this attempt appeared highly encouraging. A substantial improvement of transverse surface roughness could be achieved with all three categories of brazed wheels and the role of grit distribution pattern in obtaining good finish was thoroughly investigated.