While in the early days of metal injection moulding the entire manufacturing process and know-how from the raw materials to the final product was in the hands of the parts manufacturing companies and kept confidential, an increasing diversification has taken place recently in certain processing steps.

Feedstock systems and binder technologies now readily available

Some raw material suppliers have specialised on the production of feedstock for metal injection moulding. They can produce feedstock in larger quantities with the special know-how required for this process and have improved the batch-to-batch consistency of feedstock properties. Metal injection moulded parts producers benefit by saving the investment and labour for the preparation of their feedstock and the quality assurance associated with it.

There are also raw material suppliers offering ready-to-mould feedstocks for metal injection moulding with close specifications including the necessary know-how for binder removal and further manufacturing. Some heat treatment specialists even offer services of binder removal, sintering and heat treatment.

As a consequence, companies without any previous experience in powder metallurgy such as plastics injection moulding and investment casting companies have started to adopt metal injection moulding technology and have been successful. Manufacturers with established metal injection moulding production can also cover temporary capacity shortages by using these services.

An ever growing number of part producers, worldwide

Diversification, specialisation and availability of know-how have led to a rapid increase in the number of parts manufacturers, a higher quality of metal injection moulded products and a better acceptance of metal injection moulded parts in the marketplace, and consequently many new metal injection moulded products. The markets for metal injection moulded parts and the sales volumes of the industry are growing fast.

Today metal injection moulding is a mature, well-established, and clearly defined manufacturing technology which is widely recognized and accepted by most design engineers in the applying industries.

Inherent advantages of metal injection moulding technology

The typical metal injection moulded product combines a relatively small size, high complexity of shape, high strength, medium to high surface finish, and moderate to close dimensional tolerances.

Other properties offered by the metallic material may include a shining surface, excellent corrosion resistance, response to heat treatment, hardness and wear resistance, high electric and thermal conductivity, designed thermal expansion coefficients, special soft magnetic properties, etc.

Being a net-shape process, metal injection moulding is most competitive where costly machining operations can be avoided and where the number of parts required is sufficiently high to justify the cost of the mould. The capability to design complex shapes has often led to new part designs for metal injection moulding, combining the functions of a part assembly in a single component.

The competitiveness of metal injection moulding is limited by the relatively high raw material cost as compared to cast metals and alloys. This is the main reason why metal injection moulded parts are usually rather small, as the material cost of a small part makes up for a smaller portion of the total manufacturing cost.

The metal injection moulding process allows a high degree of automation and is therefore most competitive in volume production. Metal injection moulded parts can be designed with extremely thin walls, fine bore holes and threads, and other details. This helps to save weight and material cost.

The process is environmentally friendly and needs less energy input than other processes. Other net-shape manufacturing processes competing with metal injection moulding are investment casting, punching, machining, and joining techniques.

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