PROCESS VARIABLES IN METAL EXTRUSION, PART I: LINER FRICTION DURING EXTRUSION.
Technical rept. 1 Aug 66-30 Jun 67,
WESTINGHOUSE ASTRONUCLEAR LAB PITTSBURGH PA
Pagination or Media Count:
Three-inch diameter billets of 1018 steel, maraging steel 300 ksi, titanium alloy 6Al-4V, In - 100, and aluminum alloy 7075-0 were extruded on an instrumented 700-Ton Experimental Extrusion Press to obtain quantitative friction data under processing conditions. Friction data are presented effect of processing variables on friction values are discussed. Calculated interface shear stresses for glass-coated billets were significantly lower and more uniform than bare billets for comparable processing parameters and materials. For glass-coated billets, the nose and tail values are generally higher than the center values because of lower billet temperatures in these areas which results in an increase in viscosity or solidification of glass in these areas. The center friction values K2 represent the glass lubrication effectiveness under uniform temperature conditions. Friction stresses ranged from 2.7 to 5.8 ksi and consumed a large portion of the working pressure. For bare billets, friction stresses in the absence of galling decreased with temperature and speed of testing. Galling increased with processing temperature. Need for improved lubricants and lubrication systems for hot metal extrusion was demonstrated. Author
- Ceramics, Refractories and Glass
- Fabrication Metallurgy