A Study on a Method of Sinter Joining in the Metal Injection Moulding Process

Although Metal Injection Moulding (MIM) is a process for parts with complex designs, not all geometries are feasible. The goal of the project was to find a way to bond individually moulded parts before the sintering step and to assess the quality of the achieved sinter joining. Material Inconel 713 Low Carbon was selected for this study. The bonding of the parts was realized by applying adhesive pastes on the parts after solvent extraction. The mechanical properties of sinter joined parts were assessed by using tensile, fatigue (low cycle) and creep (stress rupture) tests. The tensile test showed that the proof stress and ultimate tensile strength were comparable to unjoined baseline material, but a drop in elongation was observed. The creep properties were similar to unjoined baseline material, but a decrease of fatigue properties was measured. A “housing” geometry that is not producible using the conventional MIM-process was manufactured as a demonstrator and it showed that it is plausible that sinter joining could be used for serial production.