Material options – how does MIM compare?

Complexity demands precision

When you think of metal injection moulding and powder metallurgy processes, a few key characteristics come to mind. These components usually have high mechanical strength, high density and perform well in corrosive environments. Due to the nature of the MIM process in particular, MIM components are exceptionally dense throughout.

But what sets the OptiMIM process apart from the rest? By far, our distinguishing factor is our custom feedstock and enhanced material performance. While many of our competitors import BASF feedstock to mould components, our OptiMIM metallurgists produce specialised, made-to-order feedstock with compositions tailored to each project. Since we produce our own feedstock, we have full control over all ingredients, recipes and, especially, the variables, enabling us to guarantee the precise composition and consistency of each component.

Why does material composition matter?

Made-to-order feedstock sounds excellent on paper. But how does the difference in quality translate into part performance?

With MIM, custom feedstock and precise powder composition contribute to an enhanced grain structure and grain boundary condition. This results in reliable, repeatable capabilities, optimal part density, the highest ultimate strength and the best elongation across all final MIM components.

Since we manufacture our own feedstock, we have the freedom to specify the metal particle size distribution and develop the binder composition for each project. This makes OptiMIM's process fully customisable to deliver the final mechanical performance and properties your application requires, rather than having to settle for the off-the-shelf properties of wrought metals.  Our technical experts can manipulate these elements to meet different performance requirements. Combined with our ability to optimise furnace recipes, this ensures that OptiMIM parts are more structurally sound and consistent, perform more reliably, and are less prone to embrittlement (cracking) than parts produced with BASF feedstock. Since we can guarantee the structure and exact material composition of each part, we can guarantee industry-leading yield strength and other relevant mechanical properties.

MIM metals: a cut above the rest

OptiMIM's precise and uniquely engineered feedstock composition, together with our proprietary grain structure, enables us to deliver both high strength and the highest elongation (ductility) performance in the industry. With other processes, design engineers are often forced to choose between optimising mechanical strength or optimising elongation—with OptiMIM, you can have both.

For example, with 17-4PH stainless steel, heat treated to H-900, OptiMIM mechanical properties deliver up to 19% better ultimate and yield strength and up to 125% higher elongation than Metal Powder Industries Federation (MPIF Std 35) industry standards.

What are my material options for metal injection moulding?

At OptiMIM, we specialise in various ferrous and non-ferrous alloys, including several stainless steel grades, copper and copper alloys, and low-alloy steel components, which account for approximately 70% of our business. We also have experience processing specialist alloys such as Cobalt-Chromium (F-75) and other high-alloy materials. But that is not all we do.

MIM materials can have their chemistries modified when used in the complex metal injection moulding process. These materials are customisable, available in a wide variety, and generally fall into four categories:

Ferrous alloys

Steels, stainless steels, tool steels, iron-nickel magnetic alloys, non-magnetic alloys and specialist alloys such as Invar and Kovar make up our ferrous alloy materials. Ferrous alloys are characteristically strong because of their iron-based composition and are often used in medical and automotive applications.

Tungsten alloys

Our tungsten alloys are characterised by high tensile strength and are naturally corrosion resistant. We often work with a tungsten-copper alloy for parts requiring a material that is heat resistant, ablation resistant, and highly thermally and electrically conductive.

Cemented carbide alloys

The MIM process is compatible with hard materials such as cemented carbides and cermets. These materials consist of hard, wear-resistant carbide and a tough, ductile metal binder, delivering a unique combination of hardness and toughness.

Special material alloys

Specialist materials frequently used in the MIM process include, but are not limited to, precious metals, titanium alloys, cobalt-chromium, nickel, nickel-base superalloys, molybdenum, molybdenum-copper and particulate composites.