The Development of Free Machining Sintered Metal Including Non-metal Additives : 3rd Report, Action of Additives

Abstract

Mixtures of ferrous metal powders (pure iron, austenitic stainless steel, ferritic stainless steel) and non-metal additives (glass, talc, boron nitride) are sintered and those materials are cut. Then, the progress of tool wear during cutting is examined, and the differences of tool life between the sintered materials are examined. Next, in order to clarify the reason why tool wear decreases with the addition of non-metal materials, the relief face after cutting is examined with an Electron Probe Microanalyzer. The conclusions obtained are as follows : (1) Tool life is prolonged by the action of additives in pure iron and austenitic stainless steel, but it is not prolonged in ferritic stainless steel. (2) Glass in the sintered metal acts as a lubricant on the relief face.