An Experimental Investigation of Stick-Slip in Hydrostatic Extrusion Using Wax to Simulate Metals

This paper describes an experimental investigation undertaken to check the explanation advanced by Rice and Iyengar for the violent pressure fluctuations which they observed during hydrostatic extrusion of wax. The results support the explanation advanced by Rice and Iyengar, confirming their suspicion that extrusion actually stops during the period of violent pressure fluctuations and reinforcing their contention that for short periods of time during each pressure pulse the velocity necessary for initiation of fluid film lubrication is exceeded, causing fluid in the form of a film to be transported into the die during those periods.