From titanium to magnesium: Processing by advanced metal injection moulding

Metal injection moulding (MIM) is a good candidate for the economic mass production of complex shaped components. This is especially true for materials that are rather expensive and difficult to form, such as titanium alloys. However, the high affinity for interstitial elements such as oxygen and carbon presents a specific challenge with regard to powder purity, handling and sintering as well as the binder system and its removal. In this paper, three examples of the manufacture of high quality samples of advanced materials are shown in detail. These comprise an optimisation of the well known Ti–6Al–4V alloy with regard to MIM processing and fatigue resistance by adding 0·5 wt-% boron powder in order to effect a reduction in grain size. Second, the MIM processing of an intermetallic alloy Ti–45Al–5Nb–0·2B–0·2C (at-%) is intended for application in turbine engines and turbochargers. Third, the status of MIM of magnesium alloys is presented. In this case, the fabrication of biodegradable implants with adjustable porosity is the main motivation for the application of MIM.