Faasikerrokset

Faasikerrokset, often translated as phase layers or diffusion layers, are a metallurgical concept describing thin regions that form at the interface between two different metals or between a metal and another material during a high-temperature process, such as welding or diffusion bonding. These layers are created by the interdiffusion of atoms from the two materials. The composition and structure of the faasikerros depend on the specific elements involved, their solubilities in each other, and the processing temperature and time.

These intermetallic compounds or solid solutions are typically brittle and can have significantly different mechanical properties compared to the parent materials. Their presence is often undesirable as they can act as crack initiation sites, reducing the overall strength and ductility of the joint. Understanding and controlling the formation of faasikerrokset is crucial in materials engineering to ensure the integrity and performance of metallic components. Factors influencing their growth include temperature, diffusion rates, and the presence of alloying elements. Researchers often investigate ways to minimize or eliminate these layers, or to mitigate their negative effects through process optimization or material design.