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[14A-T2-03] Investigation for the Ejection Property of the Conventional Lubricants Used in Powder Metallurgy Process
Keywords:zinc stearate, N,N’-ethylenebis(stearamide), ejection property, lubricity
Zinc stearate (ZnSt) and N,N’-ethylenebis(stearamide) (EBS) are conventional lubricants for powder metallurgy. While iron powder mixtures containing ZnSt exhibit excellent flowabilities, their ejection properties are inferior to those containing EBS. The purpose of this study was to identify the reason why EBS is superior to ZnSt in ejection properties. To achieve this objective, we tried to evaluate their “lubricity” and “extrusive property” individually, which seem to determine their ejection properties. “Lubricity” was investigated by sliding test on the uniform lubricant films. The friction coefficient of EBS obtained in this test was larger than that of ZnSt. “Extrusive property” was evaluated by X-ray analysis on the compact surfaces and the amount of lubricant remained on the die wall. The results of those measurements indicated that the extrusive property of EBS was greater than that of ZnSt, resulting in the better ejection property.