The Portuguese research centre which holds an industrial-like pilot production plant with process top technological equipment has been developing a Metal Injection Moulding (MIM) technology combines the potential of the injection moulding and sintering processes applied to the production of metal components. MIM production process is composed by feedstock compounding, injection moulding, debinding and sintering. Compounding is optional as there are commercial feedstock suppliers available in the market.
In this process, a quantity of a polymeric binder is combined with a metallic powder to form a composite mixture that can be moulded under heating (feedstock). In the single forming stage - by injection moulding - injection machines and moulds similar to those used for plastics are used. The biggest difference is the oversizing of the moulding cavities of about of 15-20% due to the presence of the binder, to compensate the shrinkage during the sintering process. As in plastics, moulds have multiple cavities, inserts, taps and feeding systems. In the next step, these parts are submitted to the process of removing the binder (debinding) while remaining their shape. Depending on the chemical composition of the binder, a specific debinding method is used - the most used are thermal degradation, catalytic depolymerization or solvent extraction. In the last stage, the parts are sintered, producing a solid body by densifying the powder. Then, the parts go for sintering, which is the process where the particles are combined by “semi-melting”, at a high temperature, developing the final mechanical properties of the corresponding metal. The components produced by sintering can compete with the properties of wrought materials, in part, due to the minimal residual porosity and the fine microstructure formed.
Depending on the part specification, the sintered parts can be submitted to finishing processes, such as drilling, machining, polishing or to thermal or surface treatments.
MIM application market is healthy and it is directed toward the search and development of new products where, almost always, the limit is creativity. For instance, it is used to make component redesign, with the subtraction of material, creating economic added value or weight reduction, or the design of mono-component multifunctional systems, previously consisting of several parts.
The fields of application of the components manufactured by MIM are diverse, being in constant evolution. The most significant fields of application are:
- defense and aeronautics;
- casting cores;
- mechanical systems;
- medical instruments and orthodontic elements;
- instrumentation and sensors;
- electronics and communications;
- watchmaking and jewellery;
- consumer goods.
The MIM technology offered is well developed to be commercially exploited. The technology provider has developed know-how and offers it together with processing equipment. It is available for prototype production for technology validation, as well as for any other kind of contact, mostly prior to technology transfer.
They are looking for partners to establish:
• a manufacturing agreement: they have developed the MIM technology and want to have it manufactured in their facilities.
• and/ or joint venture agreement - jointly with the partner they´ll create a new entity to develop the project, that is the manufacturing of the MIM technology;
• and/ or commercial agreement with technical assistance - It is expected that the partner is able to purchase the technology offered in order to sell metal parts to its customers, i.e,. the research centre offers their technology to be purchased, and also technical support to the technology transfer.