Influence of wheel surface speed on grindability of grinding material - Studies on ultra-high speed grinding (3rd report)

This paper describes the characteristics of the ultra-high speed grinding and the influence of wheel surface speed V on a grindability of the grinding material. The grindability can be estimated by the Cp value that is product of C and p, where C is plowing coefficient of the material and p is the yield pressure acting onto each cutting grain. The Cp value represents a plowing energy for a unit volume of the material, i.e. the specific grinding energy for plowing, and can be calculated from the normal grinding force F_n under the condition of constant v/V value (v: workpiece speed) in various wheel depth of cut Δ. In the experiment, an ultra-high speed grinding machine was used, whose maximum wheel surface speed was 400 m/s. The change of the grindability of the material with an increase of wheel surface speed V from 30 m/s to 300 m/s was recognized through the grinding tests using cast iron workpieces. The main results obtained are as follows: (1) Cp value increases with an increase of V on shallow grinding conditions. (2) Cp value decreases with an increase of V on high-efficiency conditions. This tendency becomes more remarkable at the larger Δ under a constant v/V value. (3) Wheel wear decreases as the wheel surface speed V increases.