How do laser powder DED processes differ from conventional arc welding processes?
Laser processes are generally characterized by very good controllability of the heat input. The actual heat input is limited very locally to the beam geometry on the workpiece and realizes very steep temperature gradients as well as small heat-affected zones on workpiece surfaces and in the workpiece volume. Lasers emitting with continuous power can also be modulated very quickly in their output power, so that adaptive processes, e.g. for controlling a melt pool temperature and/or size, can be realized very well. An optimally adjusted laser powder build-up welding process produces hardly any spatter, has a powder efficiency of well over 90%, does not produce any burn-in or chemical impurities in the build-up welding due to excessive mixing and achieves perfect coating results from a build-up height of just a few tenths of a millimetre. By using powder filler materials, a much greater variety of materials is available than is currently offered by wire filler materials.