The application of aluminium alloy materials for automotive heat exchangers, including engine cooling and air conditioning systems, is now widespread. To meet the industry demands of both extended service life and improved reliability for heat exchanger components, it is important that the critical factors influencing corrosion behaviour are properly understood, particularly with the trend towards downgauging of materials.
To maximise resistance to waterside corrosion, manufacturers have adopted the approach of using an internal cladding, commonly a high purity or zinc - containing alloy, to provide sacrificial protection of the core material.
Recent studies have shown that the presence of an internal cladding can, under certain conditions, promote rapid localised attack of the core alloy.
This paper will discuss the implication of these results to in-service performance of radiator units and describe the development of a rapid screening test for evaluating the performance of different core/cladding systems.