DROZDOVÁ Zita Halla-Visteon Climate Control Corporation

Automotive heat exchange applications utilizing wrought aluminum alloys which must resist exposure to corrosive exhaust gasses are becoming more prevalent in reduced hydrocarbon emission systems. This work attempts to present a test method for and demonstrate the corrosive effects of a simulated acidic exhaust gas condensate on various brazed composite wrought aluminum automotive heat exchanger test samples. Immersion testing was performed on several “long life” aluminum alloys as well as several “multiclad” structures. The long life alloys suffered from inter-granular corrosive attack; however, the attack was effectively controlled by the presence of the protective “brown band” layer formed during the brazing of these samples. The multiclad structures were found to perform quite well by experiencing only moderate surface attack. The addition of oxygenation to improve the accuracy of this simulated environmental exposure testing is also discussed.