Epitaxial solidification growth
Epitaxial solidification growth is the directed growth of solidifying melt onto the solid grains of the fusion line, exactly adopting their crystallographic orientation. This causes the base material structure to continue seamlessly into the weld.
Physical-Chemical Mechanism of Action
Epitaxial solidification growth is a process where solidifying melt arranges itself onto the solid grains of the fusion line and adopts their crystal structure. This happens under exact control of crystallographic orientation, so the new metal bonds seamlessly with the existing metal.
Metallurgical Relevance & Risks in Welding
Epitaxial solidification growth is crucial for weld quality. It prevents porosity and leads to a homogeneous, seamless joint between metals. Missing or irregular growth can cause hot cracking and fracture in the fusion line.
Workshop Practice & Instructions
To ensure epitaxial solidification growth, welding parameters such as temperature and time must be precisely controlled. Too fast cooling can interrupt growth and cause hot cracking. Too slow cooling can lead to irregular crystal structures and porosity. It is important to strictly adhere to melt time and temperature as well as cooling rate.