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New technology for the manufacturing of copper/brass heat exchangers has been developed and the first automotive radiators are already in operation in vehicles. This new technology is called CuproBraze®. One of the essential questions raised is the external corrosion resistance with reference to the present soldered copper/brass radiators and to the brazed aluminium radiators. Based on the results from electrochemical measurements and from four different types of accelerated corrosion tests, the external corrosion resistance of the CuproBraze® radiators is clearly better than that of the soldered copper/brass radiators and competitive with the brazed aluminum radiators, especially as regards marine atmosphere. Due to the relatively high strength of the CuproBraze® heat exchangers, down gauging of fins and tubes in some applications is attractive. High performance coatings can ensure long lifetime from corrosion point of view, even for thin gauge heat exchangers.

The electrooxidation of carbon black, which contains Pt electrocatalyst particles, was investigated in concentrated phosphoric acid at 0.6 to 1.0V. At the high potentials, anodic dissolution of Pt is rapid, and consequently no metal is present to catalyze the corrosion of carbon at 160 °C in 98% H3PO4. On the other hand, at 0.6V anodic dissolution of Pt is negligible, and hence it is present to catalyze the corrosion of carbon. In fact, the measurements indicate that the corrosion rate is noticeable higher than that of carbon black without Pt. These results suggest the Pt particles with surface Pt-0 may serve as an intermediary which facilitates the corrosion of carbon.