Studies on truing and dressing of diamond wheels (1st report) ― The measurement of protrusion height of abrasive grains by using a stereo pair and the influence of protrusion height on grinding performance

The protrusion height of abrasive grains in a metal bonded diamond wheel plays an important role in grinding performance. For example, the protrusion height too small causes loading easily and an increase of grinding force markedly, but the too large one causes attritious wear and releasing of cutting edges frequently. However the precise measuring method adapted to the protrusion height has not been developed. In this paper, a new 3-dimensional measuring technique [3 D method] is developed by using SEM stereo pairs. And then the effect of the protrusion height in a diamond wheel which is trued and dressed with a GC cup-truer is investigated experimentally on grinding performance of Si3N4 ceramics. The main results obtained are as follows : (1) After truing and dressing, abrasive grains protrude above the flat base of metal bond and are followed with bond-tails, the protrusion height approximates to a normal distribution. (2) Grinding force grows monotonously with an increase of grinding passes. (3) The optimum protrusion height is discussed by means of variations of grinding force, finished surface roughness and wheel wear with an increase of primary protrusion height.