WHAT IS MIM?

mim metal injection molding

This article will comprehensively introduce what is MIM Metal Injection Molding.

OVERVIEW

  1. History of MIM
  2. MIM Process
  3. Major 10 Advantages of Metal Injection Moulding
  4. 5 major disadvantages of MIM
  5. MIM materials
  6. Application of MIM
  7. Prospects of MIM

JH MIM-To be the No.1 MIM supplier in China

What is Metal injecting molding? Metal-injected molding MIM is a manufacturing process that combines plastic injection molding and metal powder metallurgy technology.

The MIM process begins by mixing fine metal powder with Powder Metallurgy Adhesive. The mixture (often called the feedstock) is then heated and injected into the MIM mold cavity under high pressure, similar to traditional plastic injection molding. The molten raw material fills the cavity and takes on the shape of the mold. Due to these advantages, it is usually used to produce metal parts with complex shapes, high precision, and excellent surface finish. It has a high-cost advantage for mass production of consistent products.

1.History of MIM

The MIM (Metal Injection Molding) process was invented by Metals & Ceramics Corporation (later renamed Parmatech Corporation), a company in the United States, in the late 1960s.

In 1979, an American company used the metal injection molding process to produce screw seal parts for passenger aircraft propellers for Boeing. It won an industry award and became well-known in the industry, marking the beginning of the rapid development of the MIM industry.

According to reports from market research institutions, the procurement scale of the global MIM industry in 2021 will be approximately US$1.8 billion. It has a profound impact on our production and life.

2. Powder injection molding process including the below process:

  1. Injection Molding design: Design the MIM moulding based on the structure and material requirements of the customer’s product.mim mould2. Mixing MIM raw materials: Select appropriate metal powder and relative binder, batch and mix according to a certain ratio (metal powder accounts for about 60%) according to the shrinkage requirements of the product, and finally form the final feed.Mixing MIM raw materials3.MIM Injection molding: Put the mixed powder material into the barrel of the injection machine. Through high temperature and high pressure, the melted powder material without fluid is injected into the mold to form the initial shape of the molded part. In the past, we needed one worker to use this machine. Trimming, and sorting products. Now JH MIM has operated automatically through robotic arms. There are 20 injection machines in the entire production workshop, and only 2-3 workers are required to inspect them. The video is as follows:

 

  1. Degreasing: After injection molding, the molded parts need to go through a heat treatment process to remove the adhesive. This step is often called degreasing.

There are three commonly used degreasing methods:

4.1. Hot air degreasing: hot air flow is used for degreasing. The molded parts are placed in a special degreasing furnace, and the polymer is evaporated by heating, turning it into a gaseous state, thereby allowing the metal molded parts to acquire voids.

4.2. Vacuum degreasing: Place the molded parts in a vacuum furnace for degreasing. By applying a vacuum under low-pressure and high-temperature environments, the polymer is volatilized under the action of heat, thereby achieving the purpose of degreasing.

4.3. Solvent degreasing: Soak the molded parts in a specific organic solvent, and dissolve the polymer through the dissolving power of the solvent. Commonly used organic solvents include acetone, methanol, etc.

JH MIM, using an oxalic acid degreasing furnace. Oxalic acid is an organic acid that uses its chemical properties to dissolve and remove adhesives in MIM molded parts. (Here is our machine)

oxalic acid degreasing furnace

Oxalic acid degreasing furnace usually consists of the following parts:

Heating system: used to provide the required heating temperature to bring the oxalic acid to the temperature of dissolving the polymer.

Control system: used to control the temperature, time, and other operating parameters of the degreasing furnace to ensure the accuracy and stability of the degreasing process.

Oxalic acid solution tank: A container containing oxalic acid solution in which molded parts can be placed for degreasing. The oxalic acid concentration and temperature in the oxalic acid solution are adjusted based on specific product requirements.

Discharge system: used to discharge waste liquid and waste gas generated during the degreasing process.

All processes have filtration systems to ensure that the production process and discharge process are green and pollution-free.

 

5. Sintering: After the product is degreased and thick, pores will appear in the middle of the metal product and require sintering. The product is placed into a vacuum sintering furnace, where sintering binds metal particles together to form a stronger structure. It is usually carried out at high temperatures, allowing the metal particles to bond with each other and form dense metal parts.

The powder metallurgy vacuum sintering furnace is a piece of equipment specially used for the sintering process in the powder metallurgy process. Vacuum sintering can be performed in an oxygen-free environment to avoid the effects of oxidation and other contaminants, thereby achieving higher-quality sintering results. The following are the general features and functions of powder metallurgy vacuum sintering furnaces:

5.1. Vacuum system: The vacuum sintering furnace is equipped with a special vacuum pump or vacuum system to establish and maintain the high vacuum environment required during the sintering process. The vacuum environment can avoid oxidation and contamination of metal powder by oxygen, water vapor, etc.sintering

5.2. Heating system: The vacuum sintering furnace is equipped with a heater, usually resistance heating or induction heating, which is used to provide the required high-temperature environment for sintering metal powder. The heating system usually has a   temperature control function to ensure the accuracy and stability of the sintering process.

5.3. Control system: The vacuum sintering furnace is equipped with an intelligent control system for monitoring and controlling key parameters such as temperature, vacuum degree, and time during the sintering process. Through accurate control of these parameters, optimization of the sintering process and best results can be achieved.

5.4. Protective atmosphere (optional): In some cases, in order to reduce the oxidation and contamination of metal powder, the vacuum sintering furnace can also provide a protective atmosphere compatible with the metal powder, such as hydrogen or nitrogen.5.4. Protective atmosphere (optional): In some cases, in order to reduce the oxidation and contamination of metal powder, the vacuum sintering furnace can also provide a protective atmosphere compatible with the metal powder, such as hydrogen or nitrogen.

injection molding service

  1. Post-processing: After sintering, the metal molded parts can undergo some subsequent processing.

Some products are deformed during the sintering process due to structural reasons, and require a shaping machine to make the product meet the drawing requirements. In the later stage, some products require additional processes such as machining, polishing, heat treatment, etc. to meet the requirements of the final product.

 

3. The MIM (Metal Injection Molding) process has the following 10 major advantages:

Some of the main advantages of the metal injection molding process include:

 

  1. Complex shapes: The MIM process can manufacture complex metal parts, providing designers with almost unlimited geometric shapes, including internal channels, thin-walled structures, and detailed processing.
  2. High precision: The MIM process can achieve high-precision dimensional control and good surface quality, reducing the need for subsequent processing procedures.
  3. Material diversity: MIM can be used to process a variety of metal and alloy materials, including stainless steel, titanium alloys, iron-based alloys, etc., providing a wide range of application options.
  4. Excellent material properties: It can produce excellent mechanical properties, such as high strength, high hardness, corrosion resistance, etc., many of which cannot be achieved by other processes.
  5. High production efficiency: The MIM process is suitable for mass production and can process multiple parts at the same time, thereby improving production efficiency.
  6. Process resource-saving: The MIM process uses powder materials. If no processing is performed after molding, the raw materials can be reused, which can save resources and reduce costs.
  7. One-time molding can be realized: Through the MIM process, the manufacturing process of one-time molding can be realized, reducing the assembly process and improving production efficiency.
  8. Design flexibility: The MIM process can adjust the shape and size by adjusting the injection mold and powder particle distribution, providing greater design flexibility.
  9. Various surface treatments: MIM parts can increase decorative effects or improve material properties through surface treatments such as polishing, electroplating, spraying, etc.
  10. Cost-effectiveness: Although the MIM process has a certain cost, it can often provide better cost-effectiveness in terms of mass production and complex shapes.

 

4.5 major disadvantages of MIM technology:

 

  1. High investment cost: Compared with some other manufacturing processes, the equipment and mold costs of the MIM process are higher. This makes the initial investment relatively high and may not be suitable for start-ups and small-scale production.

 

  1. Design limitations: Although MIM is capable of manufacturing parts with complex shapes, there are still some design limitations. For example, wall thickness ratio, slenderness ratio, and detail size will all have an impact on the feasibility of injection molding.

 

  1. High powder cost: The MIM process requires high-quality metal powder as raw material, which will lead to higher powder cost. Especially for powders of some rare metals or special alloys, the cost will be higher.

 

  1. Effect of specific surface area: The specific surface area of powder metallurgy materials will affect the feasibility and efficiency of the molding process. A higher specific surface area will lead to a more complex molding process, which may affect production efficiency and cost.

 

  1. Long cycle time: Compared with other molding processes, the MIM process has a long cycle time. Including steps such as powder preparation, mixing, injection molding, sintering, and post-processing, each step requires a certain amount of time. This may cause inconvenience for some urgent deliveries or time-sensitive projects.

 5. Commonly used MIM materials

The MIM Metal Injection Molding process is commonly used to process many metals and alloy materials, including but not limited to the following common materials:

5.1. Stainless steel (such as MIM-316L, MIM 17-4PH): Stainless steel has good corrosion resistance, high strength, and good weldability, and is often used to manufacture high-performance parts.

5.2. Titanium and titanium alloys(Ti-MIM): Titanium and titanium alloys have low density, high strength, and excellent corrosion resistance, and are widely used in aerospace, medical equipment, and automotive industries.

5.3. Nickel-based alloys (such as Inconel, and Hastelloy): Nickel-based alloys have excellent high-temperature properties, corrosion resistance, and creep resistance, and are suitable for aviation, chemical, and energy industries.

5.4. Iron-based alloys (such as Fe-Ni, Fe-Co, Fe-Cu, etc.): Iron-based alloys  (Commonly used MIM 4605 )are often used to manufacture magnetic parts, springs and wear-resistant parts, etc., and have good strength and mechanical properties.

5.5. Aluminum and aluminum alloys: Aluminum MIM has low density, excellent thermal and electrical conductivity, and is often used to manufacture lightweight parts, such as aerospace and automotive parts.

5.6 Copper and copper alloys: Copper MIM Parts have good thermal conductivity and electrical conductivity and is often used in the manufacture of electronic devices, electrical equipment, and conductive connectors.

5.7. Steel (such as low carbon steel, and tool steel): Steel is a common metal material with good mechanical properties and wear resistance, and is often used to manufacture industrial and mechanical parts.

5.8. Nickel-iron alloy (such as Invar alloy): Nickel-iron alloy has a low thermal expansion coefficient and is widely used in precision instruments, optical equipment, navigation systems, etc.

5.9. Copper-molybdenum alloy: Copper-molybdenum alloy has excellent wear resistance, high thermal conductivity and high melting point, and is often used in the manufacture of electronic devices, vacuum equipment, and electrode materials.

5.10. Aluminum bronze (such as Cu-Al alloy): Aluminum bronze has good corrosion resistance and mechanical properties and is widely used in parts manufacturing in seawater environments, such as ships and marine engineering.

In addition to the materials listed above, other metals and alloys can also be used for MIM processing, and the materials are selected according to different application needs and performance requirements. It is important to select the appropriate materials for the application and development of the MIM process based on the specific project and application.

Materials Alloy Application
low alloy steel Fe-2Ni,Fe-8Ni All kinds of structural parts in automobile, machinery and other industries
Stainless steel 316L,17-4PH,420,440C Medical equipment, watch parts
Cemented carbide WC-Co All kinds of knives, clocks, watches
Ceramic Al203,ZrO2,SiO2 IT electronics, daily necessities, clocks
Heavy alloy W-Ni-Fe,W-Ni-Cu Military industry, communications, daily necessities
Titanium alloy Ti,Ti-6Al-4V Medical, military structure
Magnetic materials Fe,NdFeB,SmCo5,Fe-Si Various magnetic components
Chisel tool steel CrMo4,M2 Various tools

6. MIM parts are common in the following 7 industries

MIM fields

The MIM Metal Injection Molding process is widely used in many fields and industries. Here are some common uses of MIM:

6.1. Automotive industry: MIM technology can be used to manufacture automotive parts, such as gears, shock absorber parts, sensors, fuel injectors and brake components. MIM-made parts typically have excellent strength and wear resistance.

6.2. Medical devices: MIM technology is widely used to manufacture medical devices and devices, such as surgical tools, implants (such as artificial joints, dental brackets), surgical parts that require high strength and complex shapes, etc.

6.3. Electronics industry: MIM-manufactured parts have many uses in the electronics industry, including connectors, terminals, sockets, electromagnetic shielding parts and sensor components, etc.

6.4. Kitchenware and household items: MIM technology can be used to manufacture high-quality kitchenware and household items, such as knives, door handles, handles, decorations, and watch parts.

6.5. Aerospace and defense: MIM-manufactured parts have important applications in the aerospace and defense fields, such as aerospace engine parts, missile components, fluid control systems, and spacecraft components.

6.6. Industrial equipment: MIM technology can be used to manufacture key components of industrial equipment, such as pumps, valves, gears, and reducer components of transmission systems, etc.

6.7. Sports equipment: MIM manufacturing technology can be used to manufacture various sports equipment, such as golf club heads, bicycle parts, car racing parts, and sports weapon parts.

In addition to the above-mentioned uses, MIM technology is also widely used in shipbuilding, energy fields (such as oil and gas extraction), power industry, and other engineering fields. MIM has the advantage of being able to achieve complex shapes and high precision, as well as offering a variety of material options, and therefore finds a wide range of applications in many industries.

7. MIM products will be more widely used in other new technology fields in the future

The following are some development prospects of MIM technology:

7.1. Automated production: With the development of automation technology and continuous improvement of processes, MIM technology is increasingly suitable for achieving large-scale and efficient production. Automation can improve production efficiency reduce costs, and promote the development of MIM technology.

 

7.2. Application of new materials: With the continuous development and application of new materials, the MIM process can use more types of materials for processing. The application of new materials will expand the application fields of MIM technology and provide the possibility to manufacture more complex and high-performance parts.

 

7.3. The combination of 3D printing and MIM: In recent years, the combination of 3D printing technology and MIM technology has received more and more attention. By combining these two technologies, a higher degree of customization and the design of complex shapes can be achieved. This combination will expand the capabilities of the MIM process and provide more innovative solutions.

 

7.4. Recycling and sustainable development: The MIM process has a high material utilization rate and can effectively recycle and reuse materials. In the context of sustainable development, MIM technology is expected to receive more attention and application to reduce resource waste and environmental load.

 

7.5. Emerging application fields: MIM technology has huge potential in emerging fields and technologies, such as new energy, aerospace, biomedicine and new materials research. The continuous development of these fields will bring more opportunities and challenges to the MIM process.

injection molding service

Overall, the MIM process has many advantages and potential, and its development prospects are broad. Through technological improvements, material innovation and market demand, MIM technology is expected to play a more important role in many fields and contribute to the development of the manufacturing industry.

 

8. JH MIM-To be the No.1 MIM supplier in China

JH MIM, as a production supplier with more than 10 years of service to overseas customers, providing the best service experience is our goal. We strive to achieve customer recognition from the following aspects:

 

8.1. Understand customer needs: Maintain close communication with customers and fully understand their needs and expectations. Understand your customers’ business and uncover their goals and challenges in order to provide them with more accurate solutions.

 

8.2. Provide customized solutions: Provide customized solutions according to the specific needs of customers. Try to meet the individual needs of customers and increase customer dependence and satisfaction on you through personalized services.

 

8.3. Provide high-quality products and services: Ensure that the quality of products and services meets or exceeds customer expectations. Continuously monitor and improve product quality to ensure product reliability, consistency, and sustainability. we pass

 

8.4. On-time delivery: Try our best to ensure on-time delivery and comply with the delivery date agreed in the contract. Plan production and logistics in advance to ensure that products are delivered to customers in time to avoid inconvenience and losses caused by delays.

 

8.5. Proactive communication: Provide project progress and relevant information to customers in a timely manner. Keep communication open with customers and promptly answer their questions and resolve their concerns. Increase trust and cooperation between your customers and you through transparent and efficient communication.

 

8.6. Provide after-sales support: Establish a sound after-sales service system to provide customers with after-sales support and problem-solving capabilities. Ensure that customers can receive timely help and support when using products, and improve customer satisfaction and loyalty.

 

8.7. Continuous improvement: Continuously improve products and services, adjust and optimize production processes based on customer feedback and market demand. Pay attention to customer feedback and suggestions and continuously improve your capabilities and service levels.

 

If you have any inquiries about MIM, please send the drawings directly and leave the rest to us.

 

 

 

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