Application of MIM metal powder injection molding in automotive field

Jul 23, 2023

MIM Metal Injection Molding (MIM) is a near-clean molding process suitable for producing small, three-dimensional complex shapes and products with special performance requirements.
Since MIM is a near-net forming process, it can not only obtain parts with high density, good mechanical properties and small surface roughness, but also produce parts with complex structure in large quantities and high efficiency, generally do not need to continue finishing, reduce the cost of parts, promote the development of automotive lightweight, reduce environmental pollution, and thus attract the attention of the automotive industry.

MIM technology, as an advanced technology in the field of powder metallurgy, is gradually replacing traditional machining technology and is more used in the production of auto parts, mainly including power transmission parts, turbochargers, fuel injectors, airbag sensor inserts, pressure sensors, electric door lock combination parts and other MIM parts.
Application of MIM metal powder injection molding machine in automotive field - You drive
1 MIM process and technical characteristics
1.1 MIM process
MIM technology consists of four main processes:
Powder and binder mixing, granulation;
② Injection molding machine injection molding;
③ Select the appropriate degreasing process;
④ Sintering parts to densify them.
1.2 MIM process characteristics
MIM is a new type of near-net forming technology of metal parts, which combines plastic injection molding technology, polymer science, powder metallurgy technology and metal material science. It not only inherits the advantages of traditional powder metallurgy and plastic injection molding, but also breaks through the limitations of traditional metal powder molding in the shape of parts. It can quickly manufacture small, complex shapes that cannot be machined by traditional methods or are difficult to machine.
Almost all materials can be produced by MIM process, MIM technology not only has the advantages of simple process, low cost, no cutting or less cutting, and high economic benefits, but also overcomes many shortcomings of traditional powder metallurgy, cutting processing, investment casting.
Application of MIM metal powder injection molding machine in automotive field - You drive
2 Application of MIM parts in automobiles
Compared with traditional machining methods, MIM parts have the characteristics of high precision, high strength, high shape complexity, diversified materials and low cost, so MIM technology has been widely used in automobiles.
2.1 Turbocharger
The turbocharger is mainly composed of turbine, pump wheel, rotor, impeller, etc., which uses the inertia force generated by the high-pressure exhaust gas discharged by the engine to drive the pump wheel to rotate, and drives the turbine to rotate through the rotor, so that the engine intake pressure increases.
In recent years, the research and development and production of turbocharger MIM parts have become the focus of scientific research work, and turbochargers are also one of the iconic parts manufactured by MIM. Its structure is extremely complex, the working environment is harsh, the precision requirement is high, but other processing methods have high cost and accuracy is not easy to control. Turbocharger parts are mainly composed of nickel-based ultra-high temperature alloy, titanium alloy and other materials, which were previously processed by traditional powder metallurgy technology.
2.2 Fuel injector
Many small precision components in automobiles can be manufactured using the MIM process. The manufacturing of composite parts is generally through forging, precision casting and other methods, the manufacturing of parts with high cost, low precision, can not achieve better economic benefits. When MIM process is used, it can improve production efficiency, improve accuracy, save materials, reduce processes and reduce costs.
The electronic gasoline injector on the automobile engine is composed of more than 20 parts, in which the magnetic circuit structure of the injector is composed of iron core, armature, magnetic guide and other parts, which are made of soft magnetic alloy materials.
Compared with traditional gasoline injectors, the overall performance of the injectors manufactured by MIM technology is improved by using iron based nanocrystalline soft magnetic powder.
2.3 Sensor
With the progress of science and technology, the types and functions of sensors applied in automobiles tend to be diversified, intelligent and miniaturized. Depending on the application area, the sensor housing is used in engine, chassis, body, navigation and other systems.
Many sensors in engine, chassis, body, navigation and other systems have been manufactured using the MIM process, such as pressure sensor components, airbag sensor inserts, oxygen sensors, steering sensors, cruise control sensor mounts, sensor housings, etc.
Compared with the precision casting process, the MIM process has the advantages of good surface roughness, high tensile strength, parts combination, reducing the number of parts, reducing costs and improving benefits.
In addition to the above parts, the ignition key, the engine rocker arm parts, the U-clamp of the steering device, the reverse synchronizer, the valve ejector rod, the piston ring, the combustion chamber cover, and the car holder are all manufactured by MIM process.
Application of MIM metal powder injection molding machine in automotive field - You drive
3 Application prospect of MIM technology in automobile
With the progress of science and technology, the main direction of automotive development is energy saving, environmental protection, comfort, intelligence and lightweight, MIM automotive products in the automotive application prospects are huge.
Using MIM technology, it is possible to design tiny auto parts into a whole or multiple components, and use MIM process to injection molding at a time, so that the parts can achieve micro, integrated, low cost and other characteristics under the premise of meeting the performance. At the same time, the parts can be manufactured with external grooves, external threads, cross holes, blind holes, reinforced plates, grooves and key pins and other complex shapes.
The application of MIM technology has played an inestimable role in the lightweight, energy-saving, functional integration, low-cost and other aspects of automobile parts, and MIM technology has a broad application market prospect in the automobile.