A note on rapid metal composite tooling by selective laser sintering

Initially the choice of material for building prototype models, experimental test pieces and functional parts was DuraForm™ PA, for a selective laser sintering (SLS) facility available to the authors. The ability of the sinterstation to build metal parts has been used to manufacture various elements of modular rapid tooling (RT) systems in development at the institute. These include both injection mould inserts and extrusion dies. The material used for the modular application was LaserForm™ ST-100, based on a stainless steel powder. During processing of this material, parts are taken from the sinterstation in a ‘green’ semi-sintered state and then go through a furnace cycle whereby they are impregnated with bronze. This produces a fully dense metal composite part. Some experiences of these early metal builds are described in this paper, including information on the data files used, build parameters and characteristics, dimensional reproduction and general part appraisal. This includes a discussion of various problems encountered, and solutions adopted to overcome them.