Metal Injection Molding Manufacturer

Metal injection molding technology

Metal injection molding, also known as MIM, is an advanced metal manufacturing process, which is a cost-effective metal parts production method with high density, complex geometries and excellent properties. As a new invention of MIM manufacturing, it combines flexibility of injection molding with strong structural integrity of powder metal sintering. The strength, economy and capacity for complex geometrical metal parts demonstrated in metal injection molding are sought-after attributes for customers. These MIM advantages promote its wide application in Electronic, Medical, Industrial, Automotive industries.

In the realm of B2B foreign trade, Metal Injection Molding (MIM) holds a crucial position. It has emerged as a game – changing technology in the metalworking industry, enabling the production of components with a level of precision and complexity that was previously challenging to achieve.

Metal Injection Molding Process

Technical Principles and Basics

Metal Injection Molding is a metal parts manufacturing process for complex structure with high precision. The process starts with finely – powdered metal, which is carefully mixed with a binder material. This mixture, known as “feedstock,” has properties similar to those of thermoplastic materials used in plastic injection molding. The choice of metal powders is extensive, with stainless steels being among the most commonly used due to their wide range of applications and excellent properties. The binder serves as a carrier, allowing the metal powders to flow and take shape during the injection molding process.

This molding process combines metal powder, injection molding and sintering technologies together, in order to guarantee MIM parts can be complex with tight tolerance as well as excellent surfaces. In addition, select metal powder with various size and shape and complement additives will create different MIM parts chemical and physical properties, binder component for every powder particle will determine final form rigidity.

Feedstock Mixing

Feedstock production is the first step in MIM manufacturing process, extraordinary fine metal powder (usually smaller than 15 microns) are mixed with binder component, which consist of primary paraffin material, secondary thermoplastic polymer and other usage materials.

Injection Molding

Once the feedstock is prepared, it is fed into a conventional injection molding machine. Here, the feedstock is heated to a suitable temperature, where it becomes a viscous fluid. Under high pressure, this fluid is injected into a mold cavity. The mold is designed with the exact shape of the desired metal component, and the injection process ensures that the feedstock fills every intricate detail of the cavity. After injection, the part, now in its “green” state, is cooled and ejected from the mold. This “green part” contains both the metal powders and the binder, and its shape closely resembles the final product, but it is still relatively weak and porous.

Debinding and Degreasing

The next crucial step in the MIM process is debinding, which involves removing the binder from the “green part.” There are several methods for debinding, including solvent extraction, thermal debinding in furnaces, and catalytic processes. Solvent debinding works by immersing the “green part” in a solvent that selectively dissolves the binder. Thermal debinding, on the other hand, involves heating the part to a specific temperature range where the binder decomposes and evaporates. Catalytic debinding uses a catalyst to accelerate the decomposition of the binder. After debinding, the part is left in a “brown” stage, which is a fragile and porous structure with a significant amount of voids filled with air (about 40 volume percent). In some cases, to simplify the process and improve handling, debinding and sintering may be combined into a single operation.

Sintering

Sintering is the final and most critical step in the MIM process. During sintering, the debound part is placed in a protective atmosphere furnace and heated to a temperature close to the melting point of the metal. At this high temperature, capillary forces cause the metal particles to bond together through a process called diffusion bonding. This results in the densification of the part, reducing the porosity and increasing its strength and mechanical properties. For example, stainless steel parts are often sintered at temperatures ranging from 1,350 to 1,400 °C (2,460 to 2,550 °F). In a vacuum sintering environment, it is possible to achieve a solid density of 96 – 99%. The end – product metal after sintering has mechanical and physical properties comparable to those of parts made using classic metalworking methods. Post – sintering heat treatments for MIM parts are similar to those used in other fabrication routes, and the high – density MIM components are compatible with various metal conditioning treatments such as plating, passivating, annealing, carburizing, nitriding, and precipitation hardening.

Secondary Operation

Secondary operation is used to improve final parts material properties, achieve tight tolerances, enhance a cosmetic surface, or assemble additional components. MIM parts can use machining, tapping, drilling, broach, grounding or welding operation same as wrought counterparts.

Advantages of Metal Injection Molding Technology

Metal Injection Molding (MIM) has several advantages over traditional metal production technologies. As 30 years continuous development of MIM technology, Zhuorui can apply this technology producing MIM parts with high volume, various alloys, different size and complex structure. Our summary of MIM advantages as following:

Cost - Effectiveness

One of the significant advantages of MIM technology is its cost – effectiveness, especially for large – scale production. The use of injection molding allows for high – volume production of complex parts in a single step. This reduces the need for multiple machining operations, which are often time – consuming and expensive. Additionally, the ability to produce small, intricate parts in large quantities makes MIM an ideal choice for industries where cost – per – unit is a critical factor. Compared to traditional metalworking processes, MIM can significantly lower production costs, making it an attractive option for B2B manufacturers looking to optimize their production costs.

Design Freedom

MIM offers unparalleled design freedom. The injection molding process enables the production of parts with highly complex shapes that would be extremely difficult or even impossible to achieve using traditional metalworking methods. Designers can create components with internal features, undercuts, and thin walls, providing greater flexibility in product design. This design freedom is particularly valuable in industries such as electronics, medical devices, and aerospace, where compact and highly functional components are in high demand. For example, in the production of miniature gears for watches or complex medical implants, MIM technology allows for the creation of parts with precise geometries and tight tolerances.

Product Quality

MIM – produced parts exhibit high product quality in terms of precision, surface finish, and mechanical properties. The use of fine metal powders and the injection molding process ensures that parts have a high degree of dimensional accuracy, with typical dimensional tolerances of ± 0.3%. The surface finish of MIM parts is also excellent, reducing the need for additional finishing operations. After sintering, the parts have a high density, which results in superior mechanical properties such as high strength, good fatigue resistance, and excellent wear resistance. These high – quality characteristics make MIM parts suitable for applications in demanding industries where performance and reliability are crucial.

Excellent Properties

It can produce fully dense metal parts close to theoretical sintering density in a complete process, so MIM parts’ physical and chemical performance is excellent. MIM parts’ mechanical strength is significant beyond powder metallurgy, in addition, it can be produced by MIM but never machined out of bar stock.

Small Size

MIM technology uses very fine metal powder to produce high density metal parts, it is most suitable for small parts manufacturing, typically weight between 0.1 and 250 grams. All these parts are difficult and arduous to manufacture by traditional ways.

Environment Economical

This technology always use suitable amount of metal materials to create determined quantity of MIM parts. There is no material waste compare to machining process, raw material utility will be close to 100% and effectively avoid waste of materials.

High Tolerance

Sintering in MIM can achieve high tolerance of ±0.5% on dimension and ±0.3% on target. Combine MIM with other processing methods, it will increase to higher dimensional accuracy.

Flexible Materials

Metal injection molding technology can be applied for most of metal materials, consider of metal special properties and economic perspective, our main applied MIM materials including:iron, steel, nickel, copper, titanium and alloy.

Delicate Appearance

Sintering surface toughness can achieve 1μm, it is perfect for further surface treatment, and get excellent dazzling appearance.

Various Application

MIM technology can satisfy various application in different industries. Its high quality ensures its wide application in environment with corrosion resistance, high strength and tolerance.

Metal Injection Molding Materials

A wide variety of metal materials can be applied in MIM process. Metal powder with various chemical composition, particle sizes and shapes will determine final MIM parts properties. Main MIM metal materials are classified into categories as following:

Ferrous alloys: steel, stainless steel, tool steel, low alloy steel, iron-nickel alloy, special ferrous alloys like Invar and Kovar.

Tungsten alloys: tungsten-copper, tungsten heavy alloys.

Nickel alloys: nickel, nickel-base superalloys.

Molybdenum alloys: molybdenum, molybdenum-copper.

Titanium alloys: titanium, titanium alloys

Hard materials: cobalt-chromium, cemented carbides(WC-Co), cermets(Fe-TiC)

Special materials: aluminum, precious metal, copper and copper alloys, cobalt-based alloys, magnetic alloys (soft and hard), shape-memory alloys

Application of Metal Injection Molding Technology

Consumer Electronics

In the electronics industry, MIM technology is widely used for the production of small, high – precision components. For example, it is used to manufacture connectors, switches, and heat sinks. The ability to produce parts with complex shapes and tight tolerances makes MIM ideal for these applications. In smartphones, MIM – made components such as SIM card holders and antenna brackets are used to ensure reliable performance in a compact form factor.

Automotive Industry

The automotive industry also benefits greatly from MIM technology. MIM parts are used in various automotive applications, including engine components, transmission parts, and safety systems. For instance, MIM – produced camshaft sprockets and valve lifters offer improved performance and durability compared to parts made by traditional methods. The high – volume production capabilities of MIM also make it suitable for the automotive industry, which requires large quantities of parts with consistent quality.

Medical Industry

In the medical field, MIM technology plays a vital role in the production of medical devices and implants. The ability to produce parts with complex geometries and high precision is crucial for applications such as orthopedic implants, dental prosthetics, and surgical instruments. MIM – made implants can be designed to closely match the natural shape and function of the human body, improving patient outcomes. Additionally, the high – quality surface finish and biocompatibility of MIM parts make them suitable for use in contact with the human body.

Industrial and Tools

Power tool MIM (Metal Injection Molding) metal parts typically include high-strength and high-precision components such as gears and shafts, which can better meet the operational requirements of power tools. Power tool parts with more complex machining, higher machining costs, and lower material utilisation are more dependent on MIM. Typical products include shaped milling cutters, cutting tools, fasteners, micro gears, and cotton loosers/weavers/trimmers parts that have been developed in recent years.

Opportunities and Collaborations in B2B Foreign Trade

The demand for Metal Injection Molding – produced parts is growing steadily in the international market. As industries continue to seek more efficient and cost – effective manufacturing solutions, Metal Injection Molding technology presents significant opportunities for B2B businesses. Manufacturers with expertise in Metal Injection Molding technology can collaborate with global partners to meet the increasing demand for high – quality, precision – made metal components. Whether it’s supplying components for the electronics, automotive, or medical industries, there is a vast market waiting to be explored. We invite potential customers and partners to join hands with us and explore the possibilities of Metal Injection Molding technology in their business operations. Together, we can unlock new opportunities and drive innovation in the global manufacturing landscape.