Definition Of Diffusion Bonding

Diffusion bonding or diffusion welding is a solid state welding technique used in metalworking capable of joining similar and dissimilar metals.

Definition of diffusion bonding. Vacuum diffusion bonding relies on temperature pressure time and ultra low vacuum levels to facilitate atomic exchange across the interface between the materials. Diffusion bonding is a solid state welding process in which no liquid or fusion phase involves and the weld joint is form in pure solid state. An experimental method of joining materials in which extremely flat and finely finished surfaces are clamped together under high vacuum for a period of hours or days sometimes at a high temperature allowing the atoms of each member to diffuse into the other. It does not melt the welding material and mostly a little plastic deformation takes place at interface surface and weld is form due to inter molecular diffusion.

Diffusion is the process of movement of molecules under a concentration gradient. Solid state diffusion bonding is a process by which two nominally flat interfaces can be joined at an elevated temperature about 50 90 of the absolute melting point of the parent material using an applied pressure for a time ranging from a few minutes to a few hours. Diffusion bonding is often the joining method of choice in the production of shim assemblies for mini or microchannel devices which are used for manifolds biomedical implants nozzles mixers and other precision assemblies. It operates on the principle of solid state diffusion wherein the atoms of two solid metallic surfaces intersperse themselves over time.

It is an important process occurring in all living beings. The process will work on similar or dissimilar materials so long as they are in intimate contact with one another. To decrease the residual stress during diffusion bonding annealing experiments simulations and investigations of residual stress by x ray diffraction xrd were performed.