MIM parts are used in a wide range of applications, including transmission and drivetrain components. The process makes use of strong metal alloys that can be hardened for strength and durability.
MIM starts with a powdered metal, mixed with what's called a binder. The resulting "feedstock" is then injection molded. Next, the part is placed in a debinding oven where the binder is vaporized.
Cost-Effectiveness
Many of the components that comprise the automotive industry require special materials to achieve their optimal performance. MIM is an excellent choice for producing these parts due to its ability to create parts with complex geometries and specialized alloys. It is also highly cost-effective when produced in large quantities, making it an ideal solution for the production of automotive electronics and sensors.
Engineers can produce parts with high accuracy using MIM that cannot be efficiently manufactured through machining processes. These include small, complex shapes and thin-walled parts. For example, the pinion ring that goes into the metering valve in a diesel fuel pump is manufactured with MIM. This part requires precise profiles and complex geometries that cannot be easily or economically produced through machining.
Manufacturers should ensure they have detailed cost models and process capabilities to understand the cost of different technologies, including MIM. This will help them optimize their designs and select the most appropriate manufacturing process.
High Tolerances
MIM is a great option for small, precise components that need to fit together. However, the tight tolerances can cause an increase in prices. This is due to additional inspections and fabrication work that need to be done on the part.
A MIM supplier can help engineers determine a tolerance level that is suitable for their application. This helps reduce costs and improve turnaround time. It also allows engineers to develop prototypes for functional testing and low-volume production before giving the go-ahead for high-volume manufacturing.
MIM parts are amenable to secondary operations like heat treating, reaming, coining, machining, and identity marking that would be performed on wrought or cast metals. They have strong dimensional stability, and are resistant to cracking. This makes them perfect for applications that require high strength and durability. This includes automotive, medical, aerospace, and firearms industries. Rising defense spending in the U.S and combat activities in Middle Eastern countries are expected to boost demand for firearms in the near future.
Durability
In the MIM process, molds are designed to fit a specified design for a part. They’re not as versatile as the tooling used in metal machining, which can be modified to accommodate changes in designs. That’s why it takes a significant amount of engineering time and money to produce the exact "recipe" that will deliver an in-spec finished part with a given mold.
Once the mold is dialed in, the MIM part goes through a series of operations that include molding, compounding, debinding and sintering. After sintering, the parts are subjected to heat treatment and tempering (just like any other metal part). They’re then polished and subjected to dimensional inspection, just as with machined parts. This includes tensile and yield strength testing, surface hardness measurements and chemical analyses. It also includes X-ray and non-destructive testing to look for cracks. This information is important to a manufacturer because it helps them ensure that their parts are of the highest quality possible.
Flexibility
MIM is a great option for producing small, intricate metal parts that cannot be produced efficiently using other production processes. In addition, it can eliminate assembly steps like screws, adhesive bonding, soldering, and welding, and reduce part weight.
Another benefit of MIM is that it allows engineers to incorporate a wide variety of metal materials into their designs. This allows them to design more complex components and improve the overall performance of their products.
However, there are some situations where MIM is not the best option for a particular product. First, it is important to consider whether the part requires frequent design changes. MIM relies on specialized tooling, which can take weeks or months to produce. This can be expensive for prototypes, or may not be practical if the design is changed frequently. This is a key consideration for engineers who want to use the MIM process in their manufacturing processes. In these cases, they should look into alternative processes such as 3D printing.
