Surface Modification of Nickel Foams for Different Applications

Nickel and nickel alloy foams are excellent substrate materials for energy and chemical technology. Depending on the intended application, the surface area of the nickel foam must be increased and the structure of the foam adapted or modified to achieve best performance. Powder metallurgical deposition of coatings using various methods like the Scattering Technique and Wet Powder Spraying is presented. These two different methods result in different foam strut morphologies, surface structures and even graded foam structures. Surface enhancement and surface alloying to modify surface properties or to activate the foams for catalytic applications are carried out in a single step or as complementary preparation steps. The resulting foams show specific properties for certain applications in areas such as electrolysis, wastewater treatment or general catalysis. The formation of Raney-Nickel, which is based on the formation of intermetallic phases on the foam surface, is presented as an example. The process chain of surface treatment, alloying and heat treatment as the final, decisive processing step for the stability of the alloyed foams is discussed and related to the different application areas of nickel foams.