Deformation of Two Phase Al-Fe and Al-Ni Alloys

Abstract

Aluminum alloys are presently used extensively as a conductor material for overhead transmission wires. Their lack of strength must be compensated by using a reinforcing agent, namely steel. The aim of this thesis was to investigate the possibility of deforming Al-Fe and Al-Ni alloys in order to produce high strength, high conductivity wire product. The main goal was to produce a two phase Al alloy wire with adequate strength so that the wire would be self supporting as an overhead electrical power transmission line. The Al-Fe and Al-Ni two phase alloy rods were Ohno cast to provide directional solidification. In both alloys, wire drawing was unsuccessful due to fiber fracture and damage accumulation during drawing. The Al-Fe alloy was subjected to hydrostatic extrusion in an attempt to induce co-deformation of the matrix material and the brittle intermetallic second phase, Al6Fe. Hydrostatic extrusion proved to be successful in inducing some deformation of the Al6Fe and provided valuable initial insight into the investigation of the deformation of Al6Fe. The final stage in the development of an aluminum alloy for use as a self supporting overhead transmission wire was the development of a “macrocomposite”. This macrocomposite was a combination of an Fe rod 4 mm in diameter and a tube of aluminum 8 mm in diameter. This macrocomposite was successfully cold worked to achieve an overall yield strength of 395 MPa.