"Is laves phase always an undesirable phase? Does it happen in all metals during a weld?"
Laves phase is a tcp phase that precipitates from iron and nickel base alloys upon heating to elevated temperatures (>1000F). Whether it is undesirable or not depends on desired critical application properties. Its effect is similar to that of sigma. Significant Laves phase decreases room temperature ductility and impact strength. It is somewhat neutral with respect to S-R strength. Based on kinetics, it should not precipitate during welding.
|| << return to the previous page ::