As technology advances, more materials and manufacturing processes come into existence that makes life easier for us. But with it comes the necessity to choose between them, in terms of pricing, the quality of the final product, and a lot more.
Two of those processes that we are going to compare here are Metal Injection Molding (MIM) and Die Casting. Both processes are used to create metal parts, but they differ significantly in various aspects.
What is Metal Injection Molding (MIM)?
Metal Injection Molding (MIM) is a manufacturing process used to create complex metal parts that have precise dimensions, require no further assembly, and have a high loading capacity. MIM is known for its ability to create shapes that are difficult, if not impossible, to achieve through other manufacturing processes.
The MIM process uses fine metal powders and a binder to create a feedstock that is injected into a mold. The mold is then heated to remove the binder and sinter the metal particles together. Once the sintering process is complete, the metal part is removed from the mold and further processed, if necessary.
What is Die Casting?
Die casting is a manufacturing process that involves injecting molten metal into a steel die under high pressure, allowing the metal to take the shape of the die. The result is a highly accurate, repeatable, and consistent part. The process is commonly used to create parts from non-ferrous metals such as aluminum, magnesium, and zinc.
Die casting can produce more complicated shapes than other casting processes, such as sand casting, but it is not used to create as complex geometries as MIM.
Comparison between MIM and Die Casting
Cost
When it comes to cost, MIM generally has a higher initial tooling cost. Due to the complexity of MIM molds, the cost of creating them is more expensive than creating die casting molds. However, MIM can produce parts with a high level of complexity in one operation, which can lead to cost savings in the long run.
Die casting, on the other hand, generally has a lower tooling cost but a higher per-part price. The molding process is faster than MIM, but the alloys used in die casting are more expensive.
Material Properties
MIM parts are created through a process that sinter the metal powders together, which can create a more homogenous material structure. This results in a higher density and strength, as well as improved wear resistance and dimensional accuracy.
Die-cast parts are created through a process that injects molten metal into a die, which can create internal features such as cores and ribs that are difficult, if not impossible, to achieve through other manufacturing processes. This results in stronger parts, excellent surface finishes, and high dimensional accuracy.
Lead Time
MIM can have a longer lead time due to the complexity of the molds and longer sintering cycles, which can reduce the number of parts that can be produced per day.
Die casting usually has a shorter lead time since the process is faster, and molds can be created in less time. It can produce thousands of parts per day and holds tolerances tighter than most other casting methods.
Conclusion
In conclusion, neither MIM nor die casting is objectively better than the other. Both methods have their advantages and disadvantages, but the choice depends on the specific requirements of the project. MIM is great for producing complex parts with tight tolerances, while die casting is better for high-volume production of parts with simple geometries.