Metal Injection Molding (MIM) is a metal fabrication process that produces components in a range of metal and ceramic compositions. KUKA Robotics uses MIM parts to enhance operational efficiency and quicken production rates.
Desktop Metal is a company committed to making metal 3D printing accessible to manufacturers and engineers. Indo-MIM offers design services, tooling, sintering, and materials as a full-service manufacturing partner for companies looking to scale up their metal AM operations.
Process Versatility
MIM parts are highly repeatable, which helps reduce production errors and ensures that finished products meet exact design specifications. The technology is also flexible in terms of the material that can be used. Engineers can choose from a wide selection of metals, including stainless steel, titanium alloys and cobalt chrome.
MIM is a cost-effective option for manufacturers that require high volumes of small, high-performing precision components with tight tolerances and consistent dimensions. It is especially suited for applications that require articulations or hermeticity, such as medical devices and surgical instruments.
The process requires the creation of specialized tools, including injection molds and binding fixtures. This can add weeks or months to the qualification timeline compared to machining. Moreover, frequent design changes can prove difficult to accommodate using MIM. However, the MIM process can be customized to suit specific application requirements. Moreover, incorporating an Industry 4.0 approach can streamline new part design cycle times and process development time.
Efficiency
MIM enables manufacturers to produce complex components in large quantities at a lower cost per unit than alternative processes. This scalability reduces the need for additional processing steps and associated labor costs, offsetting the initial investment required to create the mold.
The process also offers the ability to incorporate features into a part design that would be difficult or impossible with machining or casting methods. Threads, holes, and engravings can be added during the design phase, reducing the time and expense needed for post-processing.
To ensure the integrity of MIM parts, dimensional inspection can be conducted using coordinate measuring machines (CMM), optical comparators, and gauge systems. Chemical analysis using X-ray fluorescence or optical emission spectrometry can determine the exact elemental composition of the material used to make the part. Tensile testing can verify that the material meets specified tensile strength, compression, and hardness requirements. The resulting data can be used to optimize the manufacturing process.
Productivity
The MIM process generates very little waste and requires no assembly. It can also accommodate a wide range of complex geometries and specialized alloys. For example, the electronics industry uses MIM to produce computer hardware components like heatsinks and cooling fans, which require a high level of thermal conductivity. MIM allows manufacturers to use materials like copper and aluminum that are able to disperse heat quickly and efficiently.
Additionally, MIM can accommodate shape memory alloys (SMAs) like Nitinol, a nickel-titanium alloy that has the ability to return to its original state after deformation. SMAs are used for medical applications in implants and other devices because of their biocompatibility, corrosion resistance, and strength.
The MIM process is highly repeatable, yielding parts consistent in size, shape, and strength. This consistency can be further enhanced with nondestructive testing (NDT) techniques like metallography and eddy current testing. By using a dye to identify flaws, NDT methods detect imperfections and surface variations in the finished part that might affect its performance.
Safety
In addition to allowing designers to create parts with complex geometries, MIM also produces components with very tight tolerances. The process can produce dimensional accuracy on the order of +/- 0.1%, which is useful for applications that require stringent dimensional control.
MIM can be used to volume-produce parts to net shape, eliminating expensive post-production processes like machining. This allows for faster production times and significant cost savings, especially when manufacturing large quantities of a part.
The MIM process uses a variety of metal compositions, including nickel-iron alloys; low-alloy steels such as 4140 and 2200; and hardened tool steels. Medical applications produced by MIM often use stainless-steel materials, such as 316L and 17-4PH, which provide the necessary strength and corrosion resistance.
In order to verify the chemical composition of a MIM component, nondestructive testing (NDT) methods, such as X-ray fluorescence and optical emission spectrometry, can be utilized. This information is important for ensuring that the material meets the specified requirements for its specific application.
