A new conversion process combined with powder metallurgy and injection molding technique has been developed for application in the fabrication of air gripper finger cylinder components. CNC machining process served as a highly effective technique to fabricate pneumatic components with complex shapes and high dimensional stability. However, the machining process presents disadvantages such as low productivity and high manufacturing cost. Metal Injection Molding technology has recently been proposed to enable the production of products with complex geometry without additional machining.
Metal injection molding is capable of producing large numbers of complex metal parts economically. The MIM process has the following advantages. Firstly, it can reduce the process difficulty and material waste when manufacturing complex products. Secondly, it is more suitable for automated mass production, and the materials used in MIM are more uniform in its own microstructure. The mechanical properties are also excellent. Finally, the MIM process can select more abundant materials according to different product design needs, so it has strong material selection flexibility. Other primary benefits of MIM include:
Improved properties – MIM components are typically 95% to 99% dense, approaching wrought material properties. MIM components achieve greater strength, better corrosion resistance, and improved magnetic properties when compared to conventional powder metallurgy process.
Design freedom – MIM offers design flexibility similar to plastic injection molding. Geometrically complex parts that cannot be produced using the conventional powder metal processes without secondary machining are possible using the MIM process.
Enhanced details – MIM provides intricate features such as dovetails, slots, undercuts, internal and external threads, and complex curved surfaces. MIM can produce cylindrical parts with greater length-to-diameter ratios.
Reduced assemblies – The MIM process can be used to combine two or more simpler shapes into a single, more complex component to minimize assembly costs.
At present, lots of air gripper finger cylinder components are being produced by MIM technology. For example, using metal injection molding, the pneumatic guide rail made of 440C can meet the hardness requirement of 57-60, without secondary operation.