Direct Selective Laser Sintering of Superalloys

The advantages of powder metallurgy lie within the large degree of freedom for material design and thus is especially used in the production of high performance parts. Layer manufacturing is an appropriate method to produce complex parts rapidly. Direct Selective Laser Sintering (SLS) presents a technology which combines both benefits. Therefore many efforts are done today to qualify new materials for SLS [DAS 98, MEI 99, OVE 01, WOL 00]. Particulary materials, which are hard to cut, to cast or to shape in any else matter, are of interest. In the presented paper investigation results on Selective Laser Sintering of metals are shown on the basis of the nickel base alloy INCONEL™ 718. First, a process model has been created to discribe the mechanisms of SLS of metals. On the base of the model, process simulations and experimental investigations have been performed. In some cases, affiliating a heat treatment after the laser sintering step is favorably to improve the metallic structure and thus has also been tested. Finally, the metallograhic structures and mechanical properties were analysed.