Aluminum Wire by Cold Hydrostatic Extrusion

Electrical grade aluminum wire was made by hydrostatic extrusion. Extrusion ratios ranged from 2.5:1 to 630:1. The surface finishes, diametric variations, and electrical and mechanical properties were found to compare favorably with aluminum wire drawn through conventional dies at lower composite reductions. Several process variables, including the effects of an external draw stress, die angle, and land length of die, were also investigated. The extrusion pressures and yield strengths of the extruded wires were theoretically calculated, using Pugh’s analysis for the total work done and the total strain in hydrostatic extrusion. These values were compared with the experimental results.