The Lubricating Effect of Non-Metal Inclusions in Metal Cutting

Abstract

It is well known that inclusions in the workpiece have great influence on machinability. At the first stage, the lubricating ability of various non-metal materials was tested at an elevated temperature (700∼800°C). At the second state, a mixture of ferrous metal powders and non-metal additives was sintered, and a cutting test of these sintered materials was done. The coefficient of frictions at the tool-chip interface in cutting were examined, and the most effective additives were found. The conclusions obtained in this experiment are as follows : (1) The coefficients of friction at the tool-chip interface are able to reduce effectively by adding non-metal materials as an inclusion. (2) It is estimated that the most effective additives are lithium oxide, boron nitride, glass and tellurium oxide. Glass and boron nitride are the most prospective materials for improving machinability.