Diffusion bonding

Diffusion bonding or diffusion welding is a solid-state welding technique used in metalworking, capable of joining similar and dissimilar metals. It operates on the principle of solid-state diffusion, wherein the atoms of two solid, metallic surfaces intersperse themselves over time. This is typically accomplished at an elevated temperature, approximately 50-75% of the absolute melting temperature of the materials.^[1][2] A weak bond can also be achieved at room temperature.^[3] Diffusion bonding is usually implemented by applying high pressure, in conjunction with necessarily high temperature, to the materials to be welded; the technique is most commonly used to weld "sandwiches" of alternating layers of thin metal foil, and metal wires or filaments.^[4] Currently, the diffusion bonding method is widely used in the joining of high-strength and refractory metals within the aerospace^[1] and nuclear industries.^{[citation needed]}