A Modification of the NOCOLOK™ Flux Brazing Process to Produce Superior Corrosion Resistance or Black Surfaces.

Brazing of aluminum automotive heat exchangers with NOCOLOK™ non corrosive flux is well established throughout the world. A modification of this, results in substantially improved corrosion resistance. It is based on the controlled introduction of dry air into an inert atmosphere brazing furnace soon after the completion of the braze. Separately, the use of CO₂ as the oxidant in a similar cycle, produces black surfaces. The feasibility of both processes has been demonstrated on radiators, condensers and oil coolers in a laboratory batch furnace.

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