Segregation-free iron mixed powder containing an excellent lubricant effective for reducing the ejection force at compaction

摘要

A new segregation-free iron mixed powder containing an excellent lubricant LEX has been developed. LEX is highly effective for reducing the ejection force and consequently permitting easy extraction of a green compact from a die cavity after compaction in comparison with conventional lubricants such as zinc stearate (ZnSt). For example, the binder-treated mixed Fe-2.0mass%Cu-0.8mass%graphite powder mixed with 0.4mass% LEX yielded 30% lower ejection force than that of ZnSt at a compaction pressure of 588MPa. The new lubricant LEX reduces the sticking of compact to a die wall, therefore, it makes possible to improve the production yield of large complex shaped compacts. The mechanism of reducing ejection force above observed after the compaction of the developed segregation-free powder was probably due to the die lubrication effect by LEX extruded to the die wall from the inside of a green compact during compaction.