Abstract
In this paper, the stresses distribution upon the tool-chip contact surface at the transient cutting process of milling are analyzed by the photoelastic experimental method. The main results are as follows. That is, the distribution of normal stresses σx on a rake surface of cutter in the dry milling show a increase in a nearly beeline toward the pointed cutting edge of a cutter tooth from the chip separating point at the case of gradually increasing undeformed chip thickness, but σx show a marked increase at the neighborhood of pointed cutting edge on the case of gradually decreasing undeformed chip thickness. On the other hand, the distribution of shear stresses τxy are always nearly similarity, namely these values are gradually increasing to the middle part of tool-chip contact area from the chip separating point and have holded a constant value to the pointed cutting edge from this part after that. However, when make use of colza oil as cutting fluid, the distribution of both σx and τxy are always nearly similarity and the constant value of τxy become to comparatively small. And then, the parallel stresses of rake surface σy act always as compression stress on the tool-chip contacted face, while work as tensile stress on the free rake surface. Moreover, the tool-chip contact lengths in dry cutting are more and more increasing with the advance of cutting, these lengths, although, are nearly determined only by the undeformed chip thickness, when use of colza oil.
