The Effect of Contact Time on Forces, Wheelwear Rate and G-Ratio During Internal and External Grinding

Two wheel sizes of equal Elastic Modulus were used for internal and external grinding at conventional and high wheelspeed. At low metal removal rates, wheel dulling occurred raising forces while at nigh removal rates the wheels sharpened, reducing forces. In between, regions of stability existed. The dulling and sharpening conditions were clearly shown by wheelwear behavior. Abrasive dulling was accompanied by a reduction in wheelwear rate with time and sharpening by an increase in wheelwear rate. In the stable region, wheelwear rates decreased slightly with time. Previously-published equations describing metal removal rate and wheelwear rate vs. normal force relationships were used to predict these results. They worked especially well for the GRatio vs. Metal Removal Rate relationship.