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Clad metals are metallurgical materials systems comprised of two or more metals or alloys which are metallurgically bonded to form a single material. This results in specific and unique properties of the clad metal system which are not available in a monolithic metal or alloy. Historically, they have been used for many decades by the automotive industry but the cladding process as well as the ability to design specific properties into a clad system are not well understood. This paper describes the cold roll bonding process for fabrication of clad metals. The mechanism of bond formation and limitations of the process are discussed. Rules for calculating a number of properties of clad metals are presented. Methods for designing clad metals to obtain unique properties for specific applications are described. The history of the use of clad metals on automobiles is also reviewed.

Vehicle heat exchangers are exposed to a number of aqueous environments ranging from inhibited coolants to seawater. Frequently, the design of the heat exchanger results in a galvanic couple between copper and a stainless steel. This couple can either prevent or promote pitting and crevice corrosion of the stainless steel member. This paper demonstrates the use of electrochemical corrosion measurement techniques to predict this behavior. Stainless steels which have acceptable, marginal and unacceptable resistance to localized corrosion when coupled to copper in aggressive environments are described. Potentiodynamic polarization curves for a variety of stainless steels were measured in artificial seawater to determine their pitting and critical protection potentials. Mixed potential measurements for these alloys galvanically coupled to copper were then made to predict the localized corrosion behavior of the stainless steel.