Clad Metal Strips and Foils Engineered for High-Temperature Performance

In order to increase the engine efficiencies in small size gas turbines and microturbines, recuperators with operating temperatures over 700°C have been developed and evaluated recently. This provides challenges to materials developers and researchers for new solutions in high temperature alloys. The alloys for recuperators should have good performance in high temperature strength, creep resistance and corrosion resistance between 700∼750°C, while their cost should be kept within a reasonable range. Traditionally, clad metals by roll bonding provide both functionality and low cost solutions in demanding corrosion resistance applications and their manufacturing has been well established in large scale production. In this work, cladding technologies, particularly roll bonding, have been reviewed. Two clad metal system approaches, e.g. simple clad metal and clad metal with diffusion alloying, applied for high temperature applications are discussed. The examples of both approaches (SOFC interconnect development, catalytic converter substrate) are presented with test results. Finally, the paper presents a preliminary feasibility study of clad metal for recuperators.