[T2] Compaction & Sintering

[14A-T2-03] Investigation for the Ejection Property of the Conventional Lubricants Used in Powder Metallurgy Process

*H. Shimamoto¹, M. Onaka¹, K. Ashizuka¹, S. Unami¹ (1.JFE Steel Corporation, Steel Research Laboratory, Stainless Steel & Iron Powder Research Department, Japan)

Keywords:zinc stearate, N,N’-ethylenebis(stearamide), ejection property, lubricity

Zinc stearate and N,N’-ethylene bis (stearamide) are conventional lubricants. While an iron powder mixture containing ZnSt exhibits excellent flowability, its ejection property was found to be inferior to that containing EBS. The main purpose of this study was to identify why EBS is superior to ZnSt in the ejection property. For this objective, we attempted to evaluate the “lubricity” and “extrusive property” of the lubricants separately, as these properties likely determine their ejection properties. Lubricity was investigated by sliding tests on a uniform lubricant film. The friction coefficient of EBS was larger than that of ZnSt. The extrusive property, which means the ability to fill the gap between the compact and die wall, was evaluated by SEM-EDX analysis of the compact surfaces. The results of those measurements indicated that the extrusive property of EBS was greater than that of ZnSt, resulting in the better ejection property.