MIM can produce complex shapes and features that are impossible to create using other metal production methods. It also has dimensional stability, which helps eliminate the need for pinning.
MIM parts can be tested for quality using inspection techniques like X-rays, optical comparators and gauge systems. Chemical analysis is also available to determine the elemental composition of a MIM component. Tensile testing is also useful for measuring mechanical properties such as strength and ductility.
MIM parts are cost-effective compared to traditional machining and casting. The overall fabrication costs depend on many factors including equipment cycle times, furnace utilization, and secondary operations. Interestingly, labor is not a key factor in the cost of MIM parts.
MIM is the manufacturing method of choice for complex shapes with tight dimensional tolerances. MIM parts can be used in a wide range of applications such as computer hardware (heatsinks, cooling fans), wearables (watch cases and lugs), automotive components (rocker arms and shift levers), medical devices (dental stents, syringes), aerospace parts (hinges and latches), and more.
MIM is also a great option for making complex shapes with shape-memory alloys. The most common of these is Nitinol, a nickel-titanium alloy known for its exceptional biocompatibility and corrosion resistance. The MIM process can be used to produce intricate Nitinol parts for a variety of applications.
The high quality of MIM parts is a key advantage over other manufacturing processes. With the right design, a MIM part can easily meet tolerance requirements that would be impossible to achieve using casting or machining.
A well-designed MIM part will often hold dimensional tolerances to within +/-.0005 inch, competing with machined parts when compared on linear dimensions under.020 inches in length. In addition, MIM can hold close tolerances on a variety of shapes and geometries, including internal threads, thin walls, and fine surface detail.
MIM also offers flexibility in material composition, allowing OEMs to select a specific alloy to meet their needs and design a part to the desired mechanical properties. For example, titanium alloys are difficult to cast, but adapt well to the MIM process. An experienced CMO partner can help OEMs select the right materials for their products to ensure they are designed to mechanical specifications. This reduces development cycles and production time, and enables automation.
Metal injection molding is ideal for complex, small-size parts that are difficult or impossible to efficiently manufacture using other metal forming processes. Parts must be under 3 inches in all dimensions with a maximum wall thickness of 3.5 ounces (or cored out to this thickness).
You can freely add cross holes, angel holes, splines and undercuts into your part design with MIM processing. You can also use a wide variety of different metals, including stainless steel, low alloy steel and soft magnetic materials as well as hardened tungsten.
MIM manufacturing is especially cost-effective for high-volume production runs, which makes it a great option for disposable sterile medical devices used to treat COVID-19 patients. These single-use products offer a cost advantage over reusable instruments that require sterilization. MIM parts can also be manufactured with internal and external threads, profiled holes, finely detailed surface textures, knurling and engravings, and identity markings. They can also be heat treated if desired, but this is not necessary as the hardness of the finished part is engineered in at the time of fabrication.
MIM parts can be used for numerous applications across a range of industries, including medical, automotive, firearms, aerospace, and industrial. Parts produced through the MIM process are used for many of the same functions as those machined from raw metal stock, and they can meet the same rigorous quality requirements. It is rare that a manufacturer would go through the considerable effort and expense of moving to MIM production if it did not have a compelling reason for doing so.
For example, titanium alloys are frequently used in medical devices due to their high corrosion resistance and biocompatibility. MIM can produce parts with intricate geometry and design features that are difficult or impossible to fabricate using traditional methods. Examples include internal and external threads, grooves, scoring, and identity marking. In addition, MIM is suitable for producing asymmetric and irregular features in a single part. This feature makes it a versatile alternative to conventional manufacturing processes, such as machining or investment casting.