Case study: K-mount for surgical camera with MIMMay 29, 2020
Metal injection molding (MIM) is a versatile metal-forming technology with the capability to produce mechanical properties nearly equivalent to wrought materials, while being a net-shape process with good dimensional tolerance control. The K-mount component outlined needed to surpass the existing welded component while remaining a cost-effective solution.
The MIM process utilizes fine metal powders that are custom formulated with a binder into a feedstock. The feedstock is granulated and fed into multiple cavities of an injection molding machine. After the “green” (un-sintered) component is removed from the injection molding machine, most of the binder is extracted by thermal or solvent processing and the rest is removed as the component is sintered (solid-state diffused) in a controlled atmosphere. More details on the MIM process can be found on PickPM.com
K-Mount for Surgical Camera
The award-winning component is a K-mount for a surgical camera. Previously manufactured with two pieces that were welded together, metal injection molding technology allowed the manufacture of a single, smooth component.
The challenge in molding this component was to develop a slide mechanism robust enough to form the y-section with ease and with precise matching to avoid any flash in the molding stage. This was accomplished by using three angular slides that matched accurately at the center. A local threaded insert is used to form the threaded hole. Unique ceramic trays are used to stage the parts during sintering to minimize distortion. The part needs smooth guideways to cable connectors and precise dimensions for correct camera placement. The part is made from MIM-17-4 PH (H900) and has a density of 7.5 g/cm3.
Previously, the part was made as two separate pieces that were subsequently welded together, which tended to create sharp edges that damaged the cable during use. Using MIM enabled the production of a single, smooth component.
Using MIM instead of competing metal-forming technologies resulted in an overall cost savings while maintaining the ability to produce over 10k components per year.
Common MIM applications include, but are not limited to, computer peripherals, medical and dental devices, automotive, firearms, electronic packaging and consumer products. MIM, conventional powder metallurgy (PM), and other PM metal forming processes can be explored on the PickPM.com website.