Dendritic Segregation
Dendrite segregation is the concentration difference of alloying elements between dendrite arms and the interdendritic spaces during the solidification process. This leads to incomplete diffusion and can cause variations in strength within the structure.
Physical-Chemical Mechanism
Dendrite segregation occurs when alloying elements do not fully diffuse between the dendrite arms and the interdendritic spaces during solidification. This leads to different concentrations of elements in different areas of the structure.
Metallurgical Relevance & Welding Risks
Dendrite segregation can cause strength variations in the structure, which in turn can lead to cracks and porosity under mechanical loads. It increases susceptibility to hot cracking and reduces material toughness.
Workshop Practice & Action Items
To minimize dendrite segregation, it is important to ensure a homogeneous melt distribution. This can be achieved by carefully selecting welding parameters, such as melting time and temperature. An optimal melting process should allow for uniform deformation of the material to promote diffusion.