Evaluation and analytical electron microscopy investigation of a plated aluminum wire for branch circuit applications

Using two-wire splices made with twist-on connectors, the connection performance of a plated aluminum wire has been evaluated over five years of operation at low duty-cycle within rated electrical and environmental conditions. Analytical electron microscopy techniques were used to physically and chemically characterize the surface of the connection test wire, a sample exposed in a controlled environmental test chamber, and a freshly stripped sample of the same wire. The test results show that the plated aluminum wire has improved connectability relative to unplated aluminum previously tested, but it is not equivalent to copper wire. Safe long-term performance of plated aluminum wire is not likely to be achieved without improvement in the integrity of the plating and/or the use of corrosion inhibitor