Powder particle attachment mechanisms onto liquid material

In order to achieve high powder and energy efficiencies of Direct Metal Deposition processes knowledge about the basic effects of the interaction of the particle on the liquid surface is mandatory. Characteristic zones on the melt pool surface were identified in high-speed images. In the melt pool area around the center of the laser beam illumination, particles immediately enter into the melt pool while in its vicinity the particles float on the melt pool until they incorporate. Closer to the solidification line, particles rest on the liquid surface and remain as surface roughness on the track after solidification.