Experiments in extrusion, Part 3 - the mechanics of extrusion of beryllium.

Abstract

The extrusion pressures determined for beryllium and mild steel over a wide range of reductions in area at temperatures between 750ºC and 1050ºC are significantly lower than those reported previously. This is attributed to better control of temperature in the work reported, the effects of container friction were assessed and the coefficient of friction between tooling and billets was estimated as 0.03 — 0.035 when using graphite lubricants. The flow of metal in extrusion through various dies was examined using gridded billets; the velocity profiles and extent of the plastic field were determined. The work was applied to a study of the shapes developed from plane interfaces in the billets during extrusion; the interface shape necessary in die original billet to produce a plane interface in the extruded section was determined and applied in the basic extrusion technique to improve the yield of product.