The Mechanical Behavior of Zinc During Machining

Abstract

It is well known that a nonzero force is obtained when cutting forces measured at different feed rates but otherwise constant cutting conditions are extrapolated to zero feed rate. In the literature, this nonzero intercept has been attributed to a ploughing effect associated with the finite sharpness of the cutting tool. However, the standard extrapolation method does not account for other variables such as strain, strain rate and temperature which also vary with feed rate and influence the work material flow stress. In this paper, the apparent flow stresses measured in high and low speed machining tests on zinc are compared with the flow stresses measured in compression tests. The results show that the flow stress measured in cutting is consistent with that measured in compression when all deformation variables are properly accounted for and that, contrary to the results obtained using the extrapolation approach, the ploughing force is negligible.