HIGH DENSITY POWDER COMPACTION USING DIE WALL LUBRICATION

摘要

We have developed technique of warm compaction using die wall lubrication that obtains high density, 99% theoretical or more, by means of a single compaction only and that achieves very low ejection force in ejecting a compact from a die and enjoying epoch-making mass-production. High density is indispensable for a high performance powder metallurgical product. Unfortunately, the unavailability of superior lubricants allowed no compaction at high pressure. We have developed a specific lubricant formed by dispersing lithium stearate in water, succeeded in ultrahigh density powder compaction by means of die wall lubricating warm compaction. This paper presents the compressibility and ejection force of pure iron powder compacted by warm compaction using die wall lubrication with the developed water dispersion lubricant, entailing the most difficult compaction. The result has disclosed the anomalous phenomenon inherent in the lithium stearate.