Multi-material part production by selective melting

Abstract A method for 3D multi-material parts production has been elaborated. The selective melting machine concept and the concept of the build platform cleaning system are presented and discussed. A method involves the selection of powders of various materials according to diameter, the successive application of layers of powder of a given thickness during the vertical displacement of a piston of a build chamber, and the programmed selective sintering/melting of a given area in the plane of each layer. When the object-sintering process is finished, the unsintered powder is removed from the build chamber, and the powders are separated according to diameter by sieving with accuracy 99%, thus separating the powders of dissimilar materials. The separated powders are returned to feed containers and are reused. The combined flexible blade and suction systems for unsintered powder removal have been elaborated, which provides cross-contamination of not more than 1%.The influence of dissolution on the accuracy of the boundaries of various metals is estimated . Results of experimental investigations of material cross-contamination are presented. An experimental multi-100 SLM machine has been constructed . The proposed method is being partially applied quite successfully by some researchers. The presented technology for the manufacture of multi-material products is applicable in all powder bed fusion systems including a selective laser melting (SLM) and electron beam melting (EBM).