Theoretical and Experimental Study of the Glass Lubricated Extrusion Process

The Ugine-Se´journet patent for glass lubrication of metals extrusion made it possible to extrude steel in large quantities. A cold pad of glass powder inserted between the die and the billet head melts progressively, providing a high viscosity glass film between the die and the metal. The authors propose a theoretical model of the lubrication mechanism: progressive melting, hydrodynamic flow, and stability of the film. The influence of process parameters is discussed and results are compared with experimental measurements.