Technology of selective laser sintering / melting (SLS/SLM) is applied for manufacturing of net shaped objects from different powders : Inox 904L, Ni625, Cu/Sn, W. Experiments were carried out on PHENIX-100 machine : 50 W fibre laser, powder is spread by a roller over the surface of a build cylinder with 100 mm diameter.
Width of laser sintered line from Inox 904L powder (powder layer thickness is 50 µm) on metallic substrate was studied applying different laser power P and beam velocity V (V=60-240mm/s) but keeping effective energy input constant P1/ V1∼P2/ V2. Accuracy of fabrication of thin walls and triangles applying different laser power and sintering velocity was studied. Critical beam velocity is defined when sintered lines start to be discontinuous and drops are produced.
Different sintering strategies were applied and compared : (a) four different orientations of “vector” of beam displacement relatively given geometry of an object to be manufactured, (b) variation of distance between scanning lines, (c) application of different strategies to fabricate internal and external parts of an object. Performance and limitations of different strategies are analysed applying the following criteria : geometrical accuracy of fabrication, porosity, microhardness. Long term stability of SLM process was controlled by fabrication of thin walled objects during 36 hours. Finally the developed technology was applied for fabrication of parts for mechanical (mini pomp), medical (dental prosthesis, implants ?), bio-medical (diagnostic equipment) applications.
The last part of the work was oriented for manufacturing of multi-material products. Two-component products (Stainless steel /Cu) with good material interface were fabricated in a two-step manufacturing cycle.