Experimental Study Regarding Compressing Process with Assisted Friction Force
Friction between powder and tools plays a major role during cold compaction of PM components with results on the inhomogeneous densification. The present work deals with a new method of compaction for PM components by using the friction force between die and compacts as an active pressing force in order to reduce the density gradient. The proposal technique consists in moving the container of the die, during pressing stage to the punch direction with a well determined speed. As a result, the friction force acts in the same sense as the pressing load with better distribution of powder flow during compaction. The experimental results of compaction parameters versus density have proved the decreasing of the density gradient by increasing die/punch speed rate. A sharp density gradient on the specimen height moving container contrarily to the punch.
Ionel Chicinaş and Traian Canta
M. Sas-Boca "Experimental Study Regarding Compressing Process with Assisted Friction Force", Advanced Materials Research, Vol. 23, pp. 177-180, 2007