Options
2009
Conference Paper
Titel
Micro metal injection moulding (micron-MIM) for medical applications
Alternative
Pulvermetallurgisches Mikrospritzgießen für medizinische Anwendungen
Abstract
In recent years the scope of the micro metal injection moulding (micro-MIM) technology has expanded from iron-based materials to a considerable range of functional materials for medical applications. In this presentation, four examples of process development for biocompatible materials are discussed. The development of the micro-MIM technology for Nickel-Titanium (NiTi) parts with phase transformation temperatures in the range of 37 deg C for biomedical applications is presented. Micro tensile test specimens were injection moulded and sintered using various processing parameters. Following a range of optimisation steps concerning moulding and sintering, relative densities of 98 % along were obtained. As a second example, micro-structuring of metallic surfaces for metal-based implants by micro-MIM were evaluated. Results on the development of moulding and sintering 316L stainless steel micro structured components using blends of micron and nano sized powders are shown. Micro surface patterns made of hexagonally arranged hemispheres with a diameter between 6 and 50 micrometer showed improved bioactivity compared to non-structured tissue control samples. As third and fourth application example implant components made of Ti and Ti-alloys are presented. The pilot scale production of a replica of the stirrup bone made by micro-MIM of Ti is shown. Microstructure and properties of the material were investigated. Additionally the development of a Ti-alloy heard valve is presented. The heart valve represents a control of the blood stream in the heart muscle. Therefore it is necessary to take the streamlined design of the final geometry of the injection moulding tool into account in order to avoid blood damages. The intention of these investigations was to demonstrate the applicability of the micro- MIM production regarding precision and reproducibility of the process and to show the processibility of different biocompatible materials for medical applications, especially implants.