Due to the continuous progress of industrialization, manufacturers are looking for a method of manufacturing metal products that is cheaper and has a higher degree of freedom in product design. The high cost and low efficiency of CNC: the low precision of the casting process; the traditional PM process, the product has poor hardness and strength, high porosity, and large structural restrictions. Neither meet the requirements. In the 1960s, a new process, MIM, combining plastic technology and traditional powder metallurgy technology, came into being.
The PM (powder metallurgy) process, the single axial rigid die press forming method, consists of three main steps, firstly, mainly with fine particles of powder; the powder is placed into the forming die from top to bottom using gravity, and a certain pressure is applied to form a raw blank with the required part shape and size, and finally the blank is sintered at high temperature to form the final metal powder products.
Conversely, MIM (Metal Injection Molding) is a new powder metallurgy technology derived from the plastic injection molding industry that uses injection molding and sintering to rapidly manufacture high-density, high-precision, structurally complex parts.
Metal injection molding vs Powder metallurgy , choice which?
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Powder raw material performance differences
MIM uses raw material powder particle size diameter of 2-15μm, while the PM raw material powder particle size of 50-100μm. but the powder particle size is fine, not only increased cost (about 1-10 times the price of PM powder), and easy agglomeration, MIM feedstock contains about 30% of the binder, increasing the difficulty of mixing uniform, and the rate of degreasing is relatively slow, thereby reducing the MIM process productivity. Finally, the finer the powder chosen, the better the surface finish of the product.
The optimal requirements of MIM for the original particle powder
| Particle size/um | apparent density/% | tap density/% | Powder shape | Length-diameter ratio |
| 2-8 | 40-45 | 50 | spheroidal | 1.2-1.5 |
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Product structure differences
Powder metallurgy productst forming process is similar to the stamping process, so the structure of the product is mostly column structure, so it is widely used in bearing parts, and gear parts. The production process of MIM is similar to the plastic injection molding
process, so the mold design is more free and suitable for a more complex product structure.
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Product cost
If the same structure of products can be produced by PM and MM process, the cost of PM will be lower than MIM.
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Product performance
As the raw material powder of MIM is much finer than the raw material powder of PM, the final product density of MIM is high, 7.6-7.8, while the density of PM is low, only 6.8-6.9. Therefore, the pores of MIM products are smaller than PM pores, and the effect of plating is better.
Learn more about the MIM manufacturing process here >>>
All in all, MIM and PM processes have their advantages, and we must choose the right production process according to the specific products.
From the table below, you can compare the two processes more intuitively, and where they are good at.
| POWDERED METALLURGY | METAL INJECTION MOLDING | |
| Powdered Particle Size | 50-100pm | 2-15pm |
| Relative Density | 92%(Max) | >95-99% |
| Wall Thickness | 2-20mm | 0.3-10mm |
| Component Complexity | Medium | High |
| Weight | 1-1000g | 0.01-200g |
| Tolerance | 0.1-2% | 0.3-0.5% |
Under what circumstances is MIM the better choice?
MIM materials are more expensive, the process required for processing is longer, and the processing equipment is more expensive. When other processes cannot produce high-density, high-precision, and high-complexity products at low cost. pass
MIM to produce is the best choice,
Especially when two or more products can be designed and combined into one product, considering the later processing, assembly, logistics and other processes, it can significantly reduce the production cost.
One-stop Metal Injection Molding Manufacturer
In each project, the goal of JH MIM is: to reduce the process and cost of secondary processing, to provide customers with high-quality MIM products at a more advantageous price.
Contact our team directly to get the professional feedbacks.