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In the field of micro-technology the production of metallic and ceramic micro-components by powder injection molding (PIM) has become a more and more established fabrication method. But in order to fulfill the demand for more complex-shaped high-precision microcomponents further development work has to be performed. This is especially true if more efficient production routes for multi-component-micro-assemblies consisting of different materials or sub-components are envisaged. To meet these challenges, investigations are performed to realize and to establish two primary shape micro-processes. These are two-component micro-injection molding (2C-MicroPIM) and sinter-joining. The realization of these technologies will lead to a markedly reduction of the efforts for handling, adjustment, and assembling of metallic and ceramic microassemblies. Furthermore, an increased integration level and functionality can be yielded. For an effective transfer of scientific results to industrial applications the whole process chain must be considered, from development and construction of the tooling as well as of the components to the quality assurance and determination of the properties of the assemblies after sintering. These primary shape processes shall enable the mutual processing of different materials within the fabrication process, so avoiding separate mounting or assembling steps. Additionally fixed and loose junctions between at least two components shall be realized.The progress in research and development will be demonstrated especially by the implementation of shaft-to-collar connections between micro-gearwheels and corresponding shafts. Regarding two-component micro-injection molding, the tool construction for shaft-to-collar connections will be presented as well as first experimental results on the properties of selected ceramic powders and feedstocks for the special requirements of the 2C-MicroPIM process. With the assembly step being performed outside the injection molding tool before sinter-joining different parts and geometries can be combined quite easily. The presented article gives an overview on the concept and on preliminary testing results for the fabrication of a shaft-to-collar-connection. Additionally, a solution for an automated assembly of a shaft and a toothed wheel outside the injection molding tool is presented.

The development of a new simulation tool for micro powder injection molding (MicroPIM) needs experimental material data and verification experiments to describe the process correctly. A new and innovative approach is to use dissipative particle dynamics (DPD) to describe the form filling process with respect to the interactions on a mesoscopic scale (Hoogerbrugge and Koelman in Europhys Lett 19 (1): [155][156][157][158][159][160] 1992). The individual parameters that enter DPD modeling of this process have to be adjusted using specially designed experiments for the injection molding process. The material properties in the standard injection molding process are primarily determined by the bulk material. In micro dimensions surface effects begin to dominate because of the large surface to volume ratio. Therefore, the surface interactions between feedstock and mold insert were studied. Finally, first observations of the injection molding experiments are shown and qualitatively compared to DPD simulation results.

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