An overview on laser welding of metal foams: techniques, advantages and challenges

Due to the manifold properties of porous materials in general, and metal foams in particular, they are increasingly used in industrial, structural and functional applications. The properties of metal foams depend on: chemical composition, metallurgical aspects, processing morphology (the type of porosity: open or closed), amount of porosity, cells size and shape. There are challenges and difficulties encountered in welding and bonding metal foams from wider use in the production of complex-shaped components. Some of the problems that associate with welding processes in metal foams are reduction in mechanical properties, intermetallic compound formation, microstructural inhomogeneity and low fatigue strength. More complicated challenges are envisaged during welding metal foams with other dissimilar materials. Laser welding technologies seem to be the most promising joining techniques. This paper presents an overview on laser welding and joining techniques involving metal foams based on laser technology in similar and dissimilar combinations, with and without filler metal. The discussion on laser welding of metal foams is presented keeping the focus on CuZn open-cell foams, lotus type porous iron, foam-filled steel sandwich beams, aluminum foam cores inside a hollow profile and sandwich panels.