Laser beam welding is an established method in the manufacturing industry. The method allows the achievement of a high aspect ratio (penetration depth to weld width) due to the deep penetration effect. The method is applied in different variations which comprise a wide spectre of materials and also a large field of applications, from the field of heavy machinery up to micro system technology. There are, however, some process-induced disadvantages which may force the user to compromise.
Laser beam welding under vacuum is a new process variation with a clearly high potential. Particularly the further development in the field of solid-state lasers up to high powers and beam qualities increase the welding results, which can be achieved in the vacuum. First results made with solid-state lasers under vacuum show that the penetration depth can at least be doubled, compared to welding in atmosphere. The tendency to spatter formation to the upper surface is greatly reduced. The weld quality is, in the same turn, increased. Especially the formation of pores with increasing weld-in depths is practically non-existent.
In this lecture, new results of laser beam vacuum welding of a fine-grained steel will be presented. This includes also the mechanical properties like hardness and toughness.