A Radiotracer Method for Studying Lubrication with Glass: A Novel Technique in High Temperature Lubrication Studies

GLASS LUBRICATION for hot extrusion of metals was first patented by M. Sejournet and is now widely used. A billet is coated with glass powder, as it emerges from the annealing furnace. This melts and protects the surface from oxidation, and also provides low friction against the container of the extrusion press. The main source of lubricant is, however, a pad of glass powder placed between the die and the billet. If the conditions are suitably chosen, this glass melts steadily during the extrusion and forms a uniform coating less than one‐thousandth of an inch thick over the extruded metal.