An experimental investigation on barreling of aluminium alloy billets during extrusion forging using different lubricants

The paper reports on an investigation of extrusion forging during cold upsetting using a suitable die of aluminium alloy (H9-6063) solid cylinders subjected to different geometrical conditions such as approach angles namely, 15°, 30°, 40° and 50°, with two different initial protrusion heights namely 10 mm and 12 mm. During experiments three geometries namely barreled cylinder, truncated cone part and protruded part or extruded part were observed. The calculations were made on the assumption that the curvatures of the barrel were in the form of a circular arc and volume constancy principle. The relationship was also established among the various parameters namely the hoop stress, the hydrostatic stress, the new geometrical shape factor, and the radius of curvature of the bulge. An attempt has been made to establish the relationship between the approach angle and extrusion height and found that the extrusion height increases with the increase in the approach angle for any given extrusion load.