MIM = Powder Metallurgy + Injection Molding MIM is a typical cross-disciplinary product that integrates two completely different processing technologies (powder metallurgy and plastic injection molding), allowing engineers to break free from traditional constraints and obtain low-cost, special-shaped stainless steel, nickel, iron, copper, titanium and other metal parts by plastic injection molding, thus having greater design freedom than many other production processes.
Basic Concepts of MIM
Metal Injection Molding, referred to as MIM (Metal Injection Molding), is a method of mixing metal powder with a binder for injection molding. It first mixes the selected powder with a binder, then granulates the mixture and then injects it into the required shape, removes the binder through degreasing and sintering, and thus obtains the metal product we want, or further perfects the product through subsequent shaping, surface treatment, heat treatment, machining, etc.
Process of MIM
The MIM process is mainly divided into five stages, including granulation, molding, degreasing and sintering, and polishing
Mixing:
Select metal powders that meet the requirements of MIM (such as ferroalloys, superalloys, titanium alloys, etc.).
Metal powder is mixed with an organic binder in a certain ratio. Usually the volume of binder is about 60% metal powder.
The mixing process is carried out in a special mixing equipment, heated to a certain temperature to melt the binder.
The mixing is carried out mechanically until the metal powder particles are evenly coated with the binder and cooled to form a granular raw material.
Granulation:
The granular raw material is fed into the machine for heating and injected into the mold cavity under high pressure.
The temperature is controlled at about 200°C to melt the binder and fully integrate with the metal powder.
The mold is designed to be multi-cavity to improve productivity, and the mold cavity size is designed to be 20% larger than the metal part to compensate for the shrinkage caused by sintering.
Molding:
The granular raw material is injected into the molded blank.
During the molding process, the mold is molded under high pressure to form a blank (green part).
The blank is demolded after cooling.
Debinding:
Debinding is the process of removing the binder from the molded part.
Most of the binder is removed by solvent extraction and other methods. The remaining binder is easily volatilized during sintering.
The debinded part is semi-permeable.
Sintering:
The parts are heated in a furnace controlled by high temperature and high pressure.
The parts are heated slowly under gas protection to remove the residual binder.
After the binder is completely removed, the gaps between the particles disappear, the parts shrink to the designed size and turn into a dense solid.
Theoretically, the sintering density is greater than 97%, and the high sintering density makes the product performance similar to that of forged materials.
Surface treatment (optional):
According to specific needs, the sintered parts are surface treated, such as heat treatment, electroplating, painting, welding or cooling.
Advantages of MIM
MIM combines the advantages of powder metallurgy and plastic injection molding, breaking through the limitations of traditional metal powder molding technology on product shape. At the same time, it uses the characteristics of plastic injection molding technology that can form parts with complex shapes in large quantities and high efficiency, becoming a near-net forming technology for modern manufacturing of high-quality precision parts, with advantages that conventional powder metallurgy, machining and precision casting cannot match.
3.1 Highly complex parts can be formed Compared with other metal forming processes, such as sheet metal stamping, powder forming, forging and machining, MIM can form parts with highly complex geometric shapes. The complex part structures that can be achieved by plastic injection molding can generally be achieved by MIM. Taking advantage of this feature, MIM has the opportunity to combine multiple parts originally processed by other metal forming processes into one part, simplify product design, reduce the number of parts, and thus reduce the assembly cost of the product.
3.2 High material utilization MIM forming is a near-net forming process. The shape of its parts is close to the final product form, and the material utilization rate is high, which is particularly important for the processing loss of precious metals.
3.3 Uniform microstructure of parts, high density and good performance MIM is a fluid forming process. The presence of adhesive ensures the uniform arrangement of powder, thereby eliminating the unevenness of the blank microstructure, and then the density of the sintered product can reach the theoretical density of its material. Generally speaking, MIM can reach 95%~99% of the theoretical density. High density can increase the strength, toughness, ductility, electrical and thermal conductivity, and magnetic properties of MIM parts. The density of parts pressed by traditional powder molding can only reach 85% of the theoretical density at most. This is mainly due to the friction between the mold wall and the powder and between the powders, which makes the pressing pressure distribution uneven, and also leads to uneven microstructure of the pressed blank. This will cause the pressed powder metallurgy parts to shrink unevenly during the sintering process. Therefore, the sintering temperature has to be lowered to reduce this effect, resulting in large product porosity, poor material density, and low density, which seriously affects the mechanical properties of the parts.
3.4 High efficiency, easy to achieve mass and large-scale production MIM uses injection molding machines to mold green products, which greatly improves production efficiency and is suitable for mass production; at the same time, the consistency and repeatability of injection molded products are good, which provides a guarantee for mass and large-scale industrial production.
3.5 Wide range of applicable materials and broad application fields Metal materials suitable for MIM are very extensive. In principle, any powder material that can be cast at high temperature can be made into parts by MIM process, including difficult-to-process materials and high-melting-point materials in traditional manufacturing processes. Metal materials that can be processed by MIM include low alloy steel, stainless steel, tool steel, nickel-based alloy, tungsten alloy, cemented carbide, titanium alloy, magnetic material, Kovar alloy, fine ceramics, etc.
Our production guarantee
Our micro metal injection molding (MIM) factory has outstanding production strength and quality assurance, and can meet the stringent requirements of different industries for high-precision, high-performance parts. We are equipped with advanced production and testing equipment, including degreasing and sintering equipment, CNC machine tools, mold equipment and measurement equipment, covering every key link of micro metal injection production. These equipment and process flow ensure the high quality and stability of the products, enabling the factory to provide customers with highly precise metal parts and achieve large-scale production.
Existing equipment
Metal Injection MIM Center Equipment – Injection, Sintering |
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Serial number | Description | Specification | Brand | Quantity |
1 | Internal mixer | V-300L | V Type | 2 |
2 | Pelletizer | M-H-5L-DCSS-H | Genyilong | 2 |
3 | Injection machine | 80T | Nissin | 8 |
4 | Injection machine | 110T | Nissin | 16 |
5 | Injection machine | 180T | Arburg | 12 |
6 | Injection machine | 180T | Haitian | 6 |
7 | Injection machine | 250T | Haitian | 5 |
Debinding & Sintering | ||||
Serial number | Description | Specification | Brand | Quantity |
1 | Debinding furnace | STZ-300L | Star Special | 4 |
2 | Sintering furnace | VM48/48/200 | Hengpu | 8 |
Degreasing and sintering equipment
In the micro metal injection molding process, degreasing and sintering are the core links to ensure product quality. Our factory is equipped with advanced degreasing and sintering equipment, which can effectively remove the binder used in the injection molding process, and through high-temperature sintering, the metal powder particles are fused into a solid entity below the melting temperature. The precise control of the degreasing process can ensure the intrinsic quality of the product, prevent problems such as pores and cracks, and ensure that the product can maintain high density and high strength in subsequent processes.
Continuous Furnace
Sintering equipment uses a precise temperature control system that can be accurate to within 1 degree Celsius, so that the product can obtain the best physical and mechanical properties during high-temperature sintering. Our sintering furnaces can adjust different atmospheres, such as hydrogen, nitrogen or vacuum environments, to meet the sintering needs of various metal materials. These sintering equipment not only ensures the full densification of metal materials, but also reduces deformation and shrinkage while improving the strength and hardness of the product, ensuring the dimensional accuracy and consistency of each part.
CNC machine tools
CNC machining technology is a key tool to improve product accuracy and complexity. Our factory is equipped with multiple high-precision CNC machine tools that can perform precise secondary processing on sintered products. CNC machine tools are equipped with advanced CNC systems and high-speed tools, which can process complex geometries and fine features with an accuracy of 0.01 mm or even higher. Through efficient CNC machining, the factory is able to provide high-quality customized products and meet customers' strict requirements for product appearance, structure and function.
Our factory's CNC machining process is supervised and executed by experienced engineers and operators who have many years of experience in micro-metal machining and are able to optimize CNC programs to improve production efficiency and reduce scrap rates. In addition, the factory also uses advanced CAD/CAM software to design and compile machining programs to ensure that the CNC machining process is highly automated, standardized and precise, thereby further ensuring the stability of product quality.
Mold equipment and technical support
In micro-metal injection molding, mold design and manufacturing are key factors in determining the molding effect and quality of the product. Our factory is equipped with advanced mold processing equipment, including precision milling machines, grinders, wire cutting equipment, etc. The mold design team has rich experience and expertise, and can carry out efficient mold design and processing for the complex structure and dimensional accuracy requirements of different products.
Mold equipment processing accuracy reference:
Serial number | Equipment | Brand/Specification | Accuracy | Quantity |
(mm) | ||||
1 | CNC milling machine | +GF+ Agie Charmilles/MILL S 500 (Switzerland) | +/-0.002 | 1 |
2 | CNC milling machine | QUICK JET/VL1 | +/-0.005 | 1 |
3 | CNC milling machine | Fanuc/A04B-0102-B112#EBMH | +/-0.005 | 1 |
4 | CNC milling machine | BJ JD | +/-0.01 | 1 |
5 | CNC milling machine | Xiehong | +/-0.01 | 2 |
6 | CNC milling machine | +GF+ Agie Charmilles/WEDM CUT E350 (Switzerland) | +/-0.002 | 1 |
7 | CNC slow wire | Sodic/ (Japan) | +/-0.002 | 5 |
8 | CNC slow wire | SSG/HSQ1 | +/-0.01 | 2 |
9 | CNC medium wire | RIJUN/FG600 | +/-0.01 | 2 |
10 | CNC medium wire | MAKINO(Japan) | +/-0.003 | 1 |
11 | Spark machine | Sodic (Japan) | +/-0.003 | 7 |
12 | Spark machine | WANG XIN/ ZHUN LI | +/-0.003 | 5 |
The factory's mold manufacturing adopts a fully digital design process, using 3D modeling and simulation software to accurately evaluate the mold structure and potential problems in the injection molding process during the design stage. Every detail of the mold will be repeatedly optimized to ensure the mold's service life, accuracy and stability. Our mold team also provides fast response services, and can modify and optimize molds according to customers' special needs, so that products can maintain high consistency in mass production.
Quality Control and Measuring Equipment
Quality control is an important link to ensure that the finished product meets customer requirements. Our factory has set up strict quality control points in every production step to ensure that each batch of products is strictly inspected. The factory is equipped with professional measuring equipment, including three-coordinate measuring machines, image measuring machines, altimeters, etc., which can accurately measure the dimensions and quality of products.
Measuring equipment
Item | Describe | Quantity |
1 | CMM | 7 |
2 | OMM | 21 |
3 | 3D scanner | 1 |
4 | Electronic altimeter | 7 |
6 | Multifunctional alcohol & rubber wear tester | 2 |
7 | RCA paper tape wear tester | 2 |
8 | Rockwell hardness tester | 2 |
9 | Vickers hardness tester | 2 |
10 | Automatic tensile tester | 5 |
11 | Hydraulic material testing machine | 1 |
12 | Precision slicer | 2 |
13 | Automatic embedding machine | 1 |
14 | Pencil hardness tester | 2 |
15 | Metallurgical microscope (Germany) | 2 |
16 | Constant temperature and humidity test chamber | 2 |
17 | Hot and cold shock test chamber | 2 |
18 | Roughness tester (Japan) | 2 |
19 | X-ray fluorescence analyzer (Japan) | 2 |
20 | Melt flow meter | 1 |
21 | Salt spray machine | 3 |
The three-coordinate measuring machine can accurately detect the shape, position and dimensional deviation of the product to ensure that each part meets the design specifications. The image measuring machine captures the subtle structure through high-definition images, which can detect tiny defects of the product and accurately measure complex shapes. Our quality inspection team will conduct comprehensive dimensional and surface quality inspections after each batch of products is completed to ensure that the accuracy and appearance of each part meet the strict requirements of customers.
At the same time, our factory has passed the ISO9001 quality management system certification and adopts a full range of quality management methods to monitor every link in the production process. Each batch of raw materials undergoes strict incoming inspection to ensure the high quality starting point of the product. During the production process, we use advanced data acquisition systems to monitor key process parameters in real time to ensure that the products remain stable and consistent in every process.
Professional Team and Production Management
In addition to advanced equipment, our factory also has a professional team of senior engineers, technicians and operators dedicated to the production of high-quality micro-metal injection molding parts. Our technical team receives professional training regularly to ensure that they can master the latest manufacturing technology and quality management methods. In terms of production management, the factory strictly follows the principles of lean production and implements 6S management to improve production efficiency, reduce waste and ensure timely delivery.
The factory's production management system tracks the production progress of each order in real time and records detailed information for each process. Through an advanced information management system, our factory has successfully obtained ISO 9001 certification, indicating that we have reached international standards in quality management. Our management system can continuously and stably provide products and services that meet customer needs.
In addition, we have also won the ISO 13485 certification, which focuses on quality management and regulatory requirements in the medical device industry. Passing this certification demonstrates the professionalism of our products in the medical field and our high commitment to patient safety.
Our micro-metal injection molding factory is equipped with advanced degreasing and sintering equipment, high-precision CNC machine tools, professional mold manufacturing capabilities and strict quality control equipment, and can provide one-stop services from mold design, material processing to finished product testing. With rich industry experience, advanced production equipment and professional quality management system, we are committed to providing customers with high-precision, high-consistency and high-reliability micro-metal injection molding products to meet the needs of various industries for high-quality parts.
Our services
Our company is committed to providing customers with a full range of services to meet the diverse needs of different customers and enhance customer experience. In order to let customers better understand our products and services, we provide free samples, professional technical support, lifetime product guarantee and customized services to ensure that customers are confident in our products and enjoy a high-quality service experience.
Free samples
In order to help customers gain a deeper understanding of the quality and performance of our products, we provide free samples to customers. Customers can personally test the materials, precision and durability of the products by actually experiencing the samples, so as to better evaluate whether our products meet their needs. We are well aware of the importance of product quality to customers, so we provide free sample services to allow customers to have a clear understanding of the products before making purchasing decisions and reduce purchasing risks.
Professional technical support
Our company's professional technical team provides customers with full technical support, from product design, mold development to production optimization, there are technical experts to provide one-on-one consulting services. Whether customers encounter questions in the design stage or need help in the production process, our technical team can respond in time and provide solutions. Our technical support is not limited to the product itself, but also involves the improvement and optimization of the manufacturing process to ensure that customers get the best production efficiency and product quality.
Lifetime product guarantee
In order to make customers more assured about the use of products, we provide lifetime product guarantee services. As long as the product is produced by our company, if the customer encounters any quality problems during use, they can contact our after-sales team, and we will provide customers with free repair or replacement services. Lifetime product guarantee reflects our confidence in product quality and our long-term commitment to customers. We hope that through this guarantee, customers will get lasting support and peace of mind in the process of using our products.
Customized service
Each customer's needs are unique, and we are well aware that standardized products may not fully meet the needs of all customers. Therefore, we provide highly flexible customized services. Whether customers need customized products of specific sizes, complex structures or special materials, our team can provide personalized solutions according to customer requirements. We work closely with customers from the product design stage to ensure that every detail of the product meets customer standards. Our customization services are not limited to product design, but also include personalized customization in packaging, logos, etc. to create a unique product experience for customers.
We are always customer-oriented and provide customers with excellent product experience through free samples, professional technical support, lifetime product guarantee and customized services. Whether it is a trial before purchase or technical support and quality assurance during use, we are committed to providing customers with first-class service.
If you have metal injection molded parts for semiconductor, medical and optical applications, please send us your drawing enquiry for further evaluation at market@xy-global.com