A New Class of High Temperature and Corrosion Resistant Nickel-Based Open-Cell Foams

A number of nickel-based and iron-based alloys have been successfully developed for applications at high service temperatures and in corrosive environments. Applications such as diesel particulate filters, heat exchangers, and catalyst supports require open-cell porous structures with tailored and uniform material and structural properties, a requirement which can be met by high temperature and corrosion resistant metallic alloy foams prepared with compositions similar to those mentioned above. A new technology that transforms pure nickel foam into an alloy foam, and which has now reached the pilot plant production stage, will be introduced. This technique starts from commercially-available nickel foam, which is uniformly coated with a pre-alloyed powder using standard powder metallurgical methods, and subsequently transformed into the desired alloy throughout the strut cross-section in a relatively short time with a carefully controlled heat treatment that utilizes transient liquid-phase sintering. This process allows for the preparation of a wide variety of foam compositions and structural features, which is important for tailoring material properties to a specific application.