A New Evaluation Method for the Measurement of Internal Corrosion Resistance in Braze Clad Alloys

Historically, the development of brazing alloys for heat exchangers has focused on improving mechanical properties, improving external corrosion resistance and retaining good brazeability. Recently, the interest has been in the measurement of internal corrosion resistance and the development of aluminum alloys that will provide good internal corrosion resistance. Previously, testing to determine the internal corrosion resistance was performed on full size units. Herein is a description of an internal corrosion test loop, which has been designed and manufactured for testing internal corrosion resistance on small coupons of material. The test results for the coupons have been compared to those of a full size radiator that was exposed simultaneously with the coupons in the same corrosion test loop. The similarity between the results validates the ability of the system to test sheet specimens prior to production trials.