Melt Pool Overhang Dynamics
The dynamics of the molten metal when building self-supporting geometries without a powder bed determines the maximum overhang angle limit through surface tension and viscosity.
Physicochemical mechanism of action
The melt pool overhang dynamics describes how liquid metal behaves on self-supporting geometries. Surface tension and viscosity of the metal determine how far the metal can overhang before it becomes unstable.
Metallurgical relevance & risks in welding
Too large an overhang can lead to instability, resulting in stress and possible cracks in the weld structure. This can impair the strength and mechanical properties of the welded construction.
Workshop practice & action guidelines
To minimize the risk of instability, the overhang angle should be limited to a maximum of 45 degrees. This can be achieved by careful design of the molten shape and the use of suitable metal forms. For complex geometries, it is advisable to use a powder bed to increase stability.