Yujiaxin Co., Ltd. uses metal injection molding (MIM) technology to achieve precision component manufacturing at lower costs

 

Date：[2024/5/16]
 

The automotive, industrial, medical, electronic, and firearms industries have a huge demand for manufactured items, which must be precise and error free: complex geometric shapes, fine surface treatments, and high tolerance performance. Common manufacturing processes can provide assistance. The products manufactured by metal die-casting production lines may require additional processing steps, which can increase costs and cause waste, while investment casting may be an expensive method.
With the increasing demand for data center capacity, enterprises are seeking the most effective methods of space utilization. Data center developers have to rethink how to design and build servers to meet the challenges of people's growing demands for computing, networking, and storage capacity. New designs tend to use smaller and more functional new components.
In the next generation data center, on the one hand, there is a shortage of power and physical space. On the other hand, in order to meet the capacity demand of the future Internet, computing, network and storage capacity must be increased. To address this contradiction, engineers must adopt next-generation high-density components in server design. These components not only need to be compact in layout, but also must be highly reliable and durable to ensure signal integrity. 
Better craftsmanship for precision components
As the saying goes, "The devil hides in the details", which is beyond doubt in the manufacturing industry. In many applications, achieving "close enough" accuracy is sufficient. Public sinks and faucets, children's metal toys, umbrella frames, galvanized steel roofs, and millions of other products can function properly with lower tolerance performance or approximate detail parameters. For metal components, there are many well-known processes that can produce the products that enterprises need.
However, there is also a demand in the industry for small, durable, and precision components, in which details determine everything. The automotive, industrial, medical, electronic, and firearms industries have a huge demand for manufactured items, which must be precise and error free: complex geometric shapes, fine surface treatments, and high tolerance performance. Common manufacturing processes can provide assistance. The products manufactured by metal die-casting production lines may require additional processing steps, which can increase costs and cause waste, while investment casting may be an expensive method.
There is a method that can achieve the desired precision results more quickly, reduce waste, and ultimately lower costs, which is metal injection molding (MIM). This process can provide the required components for the project from scratch without the need for extensive processing operations after initial production to achieve excellent surface finish, excellent corrosion resistance, and high-strength final products. MIM can also bring impressive cost savings, reducing costs by up to 50% compared to mechanical processing or investment casting methods.
Therefore, it is best to consider MIM as a competitive alternative to machining, investment casting, and powder metallurgy. It has the following advantages:
Beyond mechanical processing - reduces weight and allows for the use of harder steel. It can produce more complex individual components, thereby merging them to reduce costs and reduce processing steps.
Beyond investment casting - thinner walls, better surface finish, less secondary processing, smaller holes, higher production, and shorter delivery times.
Beyond powder metallurgy - more complex components, thinner walls, component integration, higher density, greater strength, and better corrosion resistance.
MIM can also bring amazing cost savings, reducing costs by up to 50% compared to mechanical processing or investment casting methods
Precision metal components manufactured using MIM technology
MIM interpretation
In the manufacturing industry, MIM has always been overlooked. It is a mature technology that has existed for many years, with powerful and effective functions, but for some reason, many universities do not impart MIM knowledge to engineers.
MIM uses extremely fine metal powder with a size of less than 22 microns and polymer adhesive, mixed in a ratio of approximately 6:4. Heat these mixtures and make them uniform, then cool them and make them into granular raw materials. 
The key to this process is the combination of materials, and due to the use of polymer adhesives, the resulting raw materials are somewhat similar to metal plastics or putty. In the molding process, many advantages of MIM processing capability are reflected, including complex contours, holes, small radii, logos, and text that can be incorporated into the components. In this step, the raw materials are heated and injected into the molding equipment, and the components can be generated. This forming process has almost no waste of raw materials, and due to the widespread use of automated operations, it provides a manufacturing solution with high cost-effectiveness and consistent performance. Therefore, this process is similar to plastic injection molding in many aspects, and customer familiarity with the latter can help simplify any transition operation. 
Once the components are injection molded, the process of removing the adhesive must begin. Using polymer chemistry catalysts, remove 90% of the adhesive from "green" components with good shape and dimensional integrity. In this step, the component is referred to as "brown", which is a porous matrix composed of metal powder and sufficient adhesive to maintain the shape of the component. At this stage, the weight of the components is reduced by 7% to 10% without any shrinkage. 
Then perform sintering to create a solidified metal shape. In the lower temperature range of the sintering process, residual polymer adhesive is burned off. As the heat continues to increase, the metal particle matrix begins to fuse and bond with each other, making the structure more compact and reducing porosity. After sintering, sufficient densification occurs, and the components typically have a shrinkage rate of 17% to 22%, depending on the specific material.
MIM process
MIM precautions
For components manufactured using other metal forming processes, the ones that are suitable for using MIM technology are those that require extensive machining settings or assembly operations. The main advantage of MIM is that it can produce metal components with complex geometric shapes without the need for mechanical processing. 
While MIM technology provides significant advantages, it also has certain specific requirements and characteristics. Firstly, in terms of size, the components must be able to fit within a space the size of a tennis ball. Larger components should consider using other processes. The product weight should preferably be between 0.1 and 35 grams, with a uniform wall thickness ranging from 0.030 inches to 0.250 inches, and a self-supporting geometric shape during the sintering process.
The main advantage of MIM is that it can produce metal components with complex geometric shapes without the need for mechanical processing.
Potential metal materials include stainless steel (17-4, 316, 420); Low carbon steel (FN02, FN0205, FN08, 4620, 4140, 8620), as well as soft magnetic materials (FeSi3, FN50). It can also be tool steel, controllable expansion alloy, and high-temperature alloy.
In terms of material properties, even with the use of polymer adhesives, the material composition is similar to steel parts manufactured in other ways, and has an original steel density of approximately 95% to 99%. The tolerance during the manufacturing process is plus or minus 0.5%. It is possible to achieve stricter tolerances, but it is necessary to add a small amount of material to key features and achieve feature size or position requirements through precision machining processes.
Next, consider the required annual production volume. Due to the cost of mold making and sample operation, MIM is suitable for high-yield production. If the output is low, the fixed cost per unit of product will be too high. Normally, it is recommended to estimate an annual production of 10000 pieces or higher.
The injection molding process requires a gate; The design and mold plan need to include this. Sharp angles are stress points, so it is best to have larger radius dimensions at these positions. The draft angle in component design should be between 0.5 º and 1 º to assist in component ejection. Both internal and external threads can be formed. Where possible, component design should include a flat surface for sintering. Otherwise, for highly precise geometric shaped products, customized sintering fixtures are required. 
In addition, if necessary, the manufacturing process can include secondary processing of MIM components, such as heat treatment, electroplating, and mechanical processing, most of which are carried out at third-party suppliers.
Some types of components are not suitable for MIM processes: screw machine components, stamped parts, precision stamping parts, forgings, cold heading parts, non-ferrous alloys, parts with tolerances less than plus or minus 0.002 inches, and gears.
Collaborate with MIM experts
Shenzhen Yujiaxin Technology Co., Ltd. has profound and rich experience in MIM processing, providing many advantages as a manufacturing partner. The internal engineering and technical capabilities of the company include:
Development capability
Advanced development capabilities and customer support, providing pre quotation for new product design, MIM technical training, and guiding the development of new materials and processes.
Guidance ability
The project engineer guides the development of new products and pre production validation work.
Guide industrial development
For the development of new materials and products, materials and process engineers guide the development of molding, dispensing, and sintering processes.
Efficiency improvement
Manufacturing engineers guide the production operation of new products in the most effective and consistent manner, and can identify opportunities to use automated operations. 
Exploration of Automation Opportunities
Project/manufacturing engineers lead the production of new products in the most efficient and consistent manner, and explore opportunities to use automated operations.
Quality assurance
Quality engineering personnel ensure compliance with all quality expectations and requirements, and support the validation of new product designs.
Guide testing work
Metallurgical engineering personnel guide metallurgical testing work to ensure that the mechanical properties of components meet material requirements.
Yujiaxin Co., Ltd. has independently developed a degreasing and sintering integrated furnace, greatly improving production efficiency.
Yujiaxin provides professional knowledge in automation, using robots on all presses to reduce labor, using automatic control on presses to reduce labor and improve component consistency, and using separate automation operations and 100% inspection in secondary processing operations such as mechanical processing. 
Yujiaxin Co., Ltd. manufactures molds within the company and performs good maintenance throughout the entire lifecycle of the molds, ensuring a service life of up to 1 million times. The company uses local supply sources for secondary processing such as mechanical processing, heat treatment, and component coating to improve the efficiency and responsiveness of the supply chain. 
Yujiaxin Co., Ltd. supports ISO 9001 and other quality management system certifications. It has excellent tolerance control ability and can achieve a tolerance performance of plus or minus 0.002 inches without secondary processing. And it has recognized good material consistency through the use of BASF catalyst materials, including consistency between batches and operational consistency of components.
To discover more ways to innovate using complex and economical components, please visit the official website of Yujiaxin.