Direct Laser Sintering of Metals and Metal Melt Infiltration for Near Net Shape Fabrication of Components

Direct laser sintering of metal powders is a great challenge for Rapid Prototyping (RP) because of the high potential of application, for example prototype tooling for polymer extrusion. Recent development in laser sintering of metal powders use polymer or low melting alloys as a binder phase. Postsintering to strengthen the component produces shrinkage of the part, hence the near net shape capability is limited. The combination of direct laser sintering and infiltration with metal melts allows the production of strong near net shaped components without shrinkage. A composite metal powder consisting of Ni, Cu, Sn and P was successfully sintered in a Selective-Laser Sintering unit in ambient atmosphere at room temperature. The influence of laser intensity on microstructure and sintering behaviour is discussed. Infiltration experiments were done with partially sintered samples. Full density could be achieved without shrinkage. Mechanical properties and microstructural development will be discussed.