The advantages of the metal injection molding process lie in its capability to produce mechanical properties nearly equivalent to wrought materials, while being a net-shape process technology with good dimensional tolerance control. Metal injection molded parts offer a nearly unlimited shape and geometric-feature capability, with high production rates possible through the use of multi-cavity tooling.

Advantages of MIM

  • Design Complexity: MIM offers a design flexibility equivalent to Plastic Injection Molding. Complicated parts which have cross holes, angle holes, splines, undercuts, side holes and grooves are all possible with MIM. All such intricate features can be achieved. Additionally, with MIM you can create whole parts that would often have to be created separately and assembled in post production.
  • Reduced Waste/Machining: MIM’s capability to provide net shape components eliminates many secondary machining operations.
  • Improved Physical Properties: MIM parts are typically around 97% dense, MIM parts achieve greater strength, better corrosion resistance, and improved magnetic properties when compared to conventional powder metallurgy processes.
  • Properties: As we’ve already noted, MIM is able to create fully dense or near fully dense metal parts when the process is complete, if the process is carried out correctly. It’s particularly beneficial for parts that are too small or too detailed to machine out of bar stock.
  • Economical: Unlike machining, MIM doesn’t cut away existing metal – it uses only the amount of materials that is necessary to create the product. Nothing is wasted.

Disadvantages of conventional mfg techniques

Conventional process e.g. Investment Casting (lost Wax Process) is expensive, is usually limited to small/medium casting and presents some difficulties where cores are involved.

  • Holes cannot be smaller than 1/16 in. (1.6mm) and should be no deeper than about 1.5 times the diameter.
  • Investment castings require very long production-cycle times versus Metal Injection Molding
  • Sand casting process offers very rough surface, not feasible to cast small components with Sand Casting. Investment casting process is practically infeasible for high-volume manufacturing, due to its high cost and long cycle times.
  • Investment casting is time consuming as shell moulds cannot be reused
  • Labor involved is much higher than that in MIM

Below table is self explanatory about the differences between MIM and conventional mfg processes

Tensile StrengthHighLowHighHigh
Surface FinishHighMediumHighMedium
Production VolumesHighHighLowMedium
Range of MaterialsHighHighHighMedium-High