James F. McCloskey

Effect of Process Inputs on Coating Properties in the Twin-Wire Arc Zinc Process

Relationships between process inputs and coating properties were characterized using a twin-wire arc torch spraying zinc. Specifically, standoff distance, primary and secondary atomizing gas pressures, and arc current were varied in order to determine their effects on deposition efficiency, surface roughness, coating porosity, and spray particle size. Process associations were investigated using an analysis of variance with a design of experiments approach with the intent of determining which spray parameters affect each of the aforementioned coating properties. The associations found are consistent with other studies of the twin-wire arc spray process and provide a framework for selecting process operating conditions based on desired coating properties. Such a specific outline has not been previously available.

Arc spray termination of extended foil capacitors.

Twin wire arc spray is evaluated as a termination method for the fabrication of extended foil wound capacitors. A full design of experiments is performed, analyzing various spray processing conditions and their effects on relevant electrical performance. Cross sectional metallography and electrical testing are used to evaluate potential damage caused by the deposition process as well as the overall quality of the finished capacitor sprayed under different conditions. Major findings are consistent with previously published work indicating that arc spray is a viable candidate for terminating foil capacitors.