Some Effects of Injecting Cutting Fluids Directly Into the Chip-Tool Interface

An experimental investigation in which SAE 1040 steel was cut orthogonally with fluid being forced directly into the chip-tool interface through a small hole in the rake face of the tool is described. Three fluids were used, a straight mineral oil, and the same oil containing either chlorine or sulphur. The distance of the hole from the tool tip was varied over a range of one to three times the depth of cut. Results indicate that cooling of the chip-tool interface by the injected fluid is of primary importance; and that blocking of the hole is a result of the breakdown of chloride and sulphide films caused by high temperature at the interface. An explanation of how the fluid escapes from the chip-tool interface is provided.