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DIFFUSION WELDING AND ITS PROCESS

Diffusion welding is a process that does not necessarily need heat to produce a fusion weld. Rather it needs two kinds of surfaces that can come into intimate contact under pressure. This pressure is applied for a period of  hours. In this process, although heating is not essential , if the temperature is raised, the diffusion rate will be cut sufficiently. It might take many hours to perform a certain bonding, but with heat the time element can be cut to a matter of hours of minutes.

The goldsmith has for centuries made filled gold by placing a weight on top of  a sandwich composed of silver or copper core with gold face sheets. When this is held in a furnace for a prolonged time, a permanent bond is obtained. That is what is done in diffusion bonding in principle. 

This process makes it possible to join metal to metal , metal to ceramic, and metal to metal with intermediate bonding materials, Temperatures that approach is approximately 900*C. This extreme temperature limits diffusion bonding of steel. Diffusion bonding incorporates three basic techniques practically having same principle as explained. These are : gas - pressure bonding, vacuum fusion bonding, and eutectic fusion bonding.   


Diffusion Welding




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