A technique for joining porous foam material, such as graphite, metal or ceramic foam, to a substrate is described. The substrate can be metal, a thermoset plastic or a composite material. The substrate has a melting point below that of the foam material. The two are joined together by using the foam to apply heat locally at the surface of the substrate. Some or all of the foam is heated to the appropriate temperature at or above the melting point of the substrate material. The foam and the substrate are then brought together, with the heat from the foam melting or softening the substrate material so that the substrate material infuses into the pores of the foam. As the foam cools below the melting point temperature, the substrate material solidifies to create a mechanical bond between the foam and the substrate.