What’s Application Suitable for MIM Technology

You will see many parts in more and more equipment and machinery

  1. Industrial machinery: MIM parts are used in machinery and equipment for manufacturing processes, such as pumps, valves, and gears.
  2. Sports and recreation: High-precision metal parts are essential in various sports and recreation equipment such as golf clubs, fishing reels, and gun accessories.
  3. Defense and military: MIM technology can be applied in the defense industry to produce high-precision metal parts for weapons, communication devices, and other military equipment.
  4. Robotics: MIM parts can be used to create precise, small components for robots, drones, and other automated systems.
  5. Energy: MIM parts are used in energy production and distribution, such as in oil and gas drilling equipment, solar panels, and wind turbines.
  6. Tools and hardware: MIM parts can be used in tools and hardware, such as hand tools, power tools, and locks.

MIM technology has many applications and is ideal for creating small, intricate, and complex metal parts with high precision.

medical equipment
firearms
mim Automotive application

MIM stands for Metal Injection Molding and is a process used to create complex metal parts with high precision. MIM parts have several applications across different industries, including:

  1. Automotive: MIM parts are used in engines and transmission systems where high precision is required.
  2. Aerospace: MIM parts can be used in aircraft components such as landing gears, avionics, and turbine engines.
  3. Electronics: MIM parts are used in electronic devices such as smartphones, laptops, and tablets.
  4. Medical: MIM parts are used in medical devices such as surgical instruments, implants, and dental tools
  5. Firearms: MIM parts are used in firearms manufacturing, particularly for small, intricate parts.
  6. Consumer goods: MIM parts can be found in products such as jewelry, toys, and watches.Overall, MIM technology is versatile and can be applied in various fields where high-precision metal parts are required.

MIM Process

Feedstock preparation

Metal powder is mixed with a binder material, typically a thermoplastic polymer, to create a feedstock. This feedstock has a consistency similar to toothpaste.

Injection molding

The feedstock is injected into a mold using an injection molding machine. This machine applies heat and pressure to melt and flow the material into the mold cavity

Debinding

After injection molding, the part is removed from the mold and any excess feedstock material is removed by soaking it in a solvent to dissolve the binder material.

Sintering

In this step, the molded part is heated in a furnace to a temperature near the melting point of the metal. This causes the metal particles to bond together through a process called solid-state diffusion, creating a dense and strong metal component.

Finishing

The final step involves any necessary secondary operations such as machining, plating, or polishing to achieve the desired surface finish and dimensions.

MIM Design Criteria

The design criteria for Metal Injection Molding (MIM) include using a draft angle of 1-2 degrees, maintaining uniform wall thickness between 0.5mm and 4mm, and avoiding undercuts or planning for additional operations if necessary. Additional considerations include adding fillets and radii to sharp corners, specifying surface roughness requirements, and realistic tolerances achievable with MIM technology.

Uniform

Uniform wall thickness, coring, and mass reduction are all important design considerations in Metal Injection Molding (MIM).Uniform wall thickness ensures a consistent packing process and reduces the risk of defects. Coring can be used to reduce weight and material usage while maintaining the structural integrity of the part. Mass reduction is particularly important in the automotive and aerospace industries where reducing weight can improve fuel efficiency and performance

Coring

Coring is the process of removing material from inside a part to reduce weight while maintaining its structural integrity. This can be achieved through various methods such as using hollow or partially-hollow components, or by creating a lattice-like structure within the part. Coring can help reduce material usage, production costs, and part weight, making it an effective way to optimize MIM designs. However, it’s important to ensure that the coring does not compromise the part’s strength or functionality.

Suitable for Sintering

Designing MIM parts that are suitable for sintering is crucial for ensuring high strength and quality in the final product. To achieve this, parts should be designed with features that allow for uniform shrinkage during sintering, such as uniform wall thickness throughout the part, avoidance of sharp corners or edges, minimization of undercuts, proper support structures to prevent deformation, and efficient use of space within the mold to minimize part warpage. By considering these factors in the part design process, designers can produce MIM parts that are well-suited for the sintering process and meet all necessary specifications and quality standards.

Draft

In metal injection molding (MIM), draft is the angle or taper that is added to the vertical walls of a mold cavity to facilitate easy ejection of the final part. During the MIM process, the molten feedstock is injected into the mold cavity and allowed to cool and solidify, forming the desired shape of the final part. Once the part has solidified, it must be removed from the mold cavity, which is where the draft angle comes in.By incorporating a draft angle into the mold design, the part can be easily ejected from the mold without damaging its surface finish or features. Typical draft angles for MIM parts are 1-2 degrees, although this may differ depending on the specific geometry and requirements of the part. Additionally, it is important to ensure that the draft angle is consistent throughout the part to prevent any warping or distortion during the cooling process.

Corner breaks and fillets

In metal injection molding (MIM), corner breaks and fillets are features that can be added to the part design to improve its strength, functionality, and manufacturability.Corner breaks are small chamfers or radii that are added to corners of a part to reduce stress concentrations. Sharp corners can create weak points in a part, which can lead to cracking or breaking over time. By adding corner breaks, the stress is distributed more evenly across the surface of the part, improving its durability.Fillets are curved transitions between two surfaces, typically found at the intersection of two planes or surfaces. Like corner breaks, fillets can help to distribute stress more evenly across a part, reducing the likelihood of failure. Additionally, fillets can aid in the molding process by allowing molten material to flow more easily around the mold cavity, resulting in a more consistent part.Both corner breaks and fillets are important features to consider when designing MIM parts, as they can improve the strength, functionality, and overall quality of the final product.

Ribs and webs

In the manufacturing of plastic injection molded (MIM) parts, ribs and webs are frequently used to enhance the part’s strength and rigidity. Ribs are thin, raised portions on the surface of the part that run perpendicular to the part’s primary axis, while webs are thin, raised portions that connect two or more parts of the part. Ribs and webs can help reduce warping, prevent cracking, and improve the overall structural integrity of the part. However, it’s important to be careful not to overdo it with ribs and webs, as too many can cause excessive stress on the molding tool and lead to defects in the finished product. Experts in MIM manufacturing will typically use computer-aided design (CAD) software to optimize the rib and web placement for each part, taking into account factors such as the part’s geometry, material properties, and end-use requirements. By carefully designing the part’s ribs and webs, MIM manufacturers can create parts that are both strong and lightweight, with minimal material waste.

Thread

Internal threads can indeed be molded directly into a MIM component using unscrewing cores, but this process can be quite costly and is typically reserved for high volume applications. For lower volume part applications, conventional tapping operations are often preferred.On the other hand, external threads can be molded directly onto the component, which can be a more cost-effective approach than forming the threads with a secondary operation. When designing a MIM component with external threads, it’s important to incorporate a small flat (typically around .005″ at the parting line) into the design. This recessed flat will help ensure proper mold seal-off and reduce the opportunity for parting line vestige to interfere with component function.Without the presence of a flat along the parting line, flash may develop in the root of the threads within the production of very few parts. This can lead to problems with tooling maintenance and possibly increase downtime during production.

Wall thickness

In MIM (Metal Injection Molding) parts design, the minimum and maximum wall thickness are also important factors to consider. The minimum wall thickness for MIM parts is typically between 0.25mm to 0.5mm, depending on the material being used and the dimensions of the part. A minimum wall thickness that is too thin can lead to structural weaknesses, sink marks, and other defects. Additionally, extremely thin walls can make it difficult to properly fill the mold during the injection molding process.The maximum wall thickness for MIM parts is determined by several factors, including the material being used, the overall geometry of the part, and the aspect ratio of the walls. Generally, the maximum wall thickness for MIM parts is around 4-5mm, although this can vary depending on the specific application. Design guidelines for MIM typically recommend keeping the difference between the minimum and maximum wall thicknesses at or below 10:1. This helps to ensure that the part will be both strong and lightweight. It’s important to note that designing MIM parts with consistent wall thickness throughout the part can help to reduce warping, sinkage, and other potential issues.

Flash and witness lines

Flash and witness lines are common issues that can occur during the MIM (Metal Injection Molding) process, but they can be mitigated through careful design and molding practices.Flash refers to excess material that escapes from the mold cavity and extends beyond the edge of the part. Flash can occur when the mold is not properly closed or maintained, or when there is too much pressure in the mold cavity, causing the material to overflow. Flash can weaken the part and interfere with its function. To prevent flash, it’s important to ensure that the mold is properly assembled, maintained, and closed during the molding process.Witness lines are visible seams that occur where the two halves of the mold meet. These lines can be caused by a variety of factors, including uneven filling of the mold cavity, differences in cooling rates between the two halves of the mold, and variations in material properties. While witness lines are generally considered cosmetic defects, they can sometimes indicate other issues that may compromise the structural integrity of the part. To prevent witness lines, designers should strive for even filling of the mold cavity, use proper gate size and placement, and optimize cooling to promote uniform solidification across the part.In both cases, it’s important to work with experienced MIM manufacturers who can provide design guidance, process optimization, and quality control to ensure that the final product meets all requirements.

DIMENSIONAL TOLERANCES

There are a number of variables that influence the tolerance capability of any feature in the MIM process. The tolerance capability may be below or above the +/- 0.3% noted above. There are a number of variables that need to be taken into consideration, including part design, size, shape, material, gate location, number of cavities, and mold construction methods. Material chemistry can play a greater role in tolerances if it is chosen correctly for your application.
As a starting point, MIM can produce as-sintered tolerances of: +/- 0.3% of nominal (e.g. 1.000″+/-.003), compared to investment casting which produces tolerances of: +/- 0.5% of nominal (e.g. 1000″+/-.005).

F.A.Q.

MIM Design
Yes, MIM parts need draft due to the nature of the metal injection molding process. Draft helps ensure that when a part is removed from the mold, it does not get stuck and that any details on the part are not distorted. The MIM Design Guider will help you establish a safe draft angle for your parts with guidance from our experts.
MIM powder is typically made through atomization, which involves the introduction of high-pressure gas or liquid to a molten metal source material. The atomization process breaks the molten metal into small droplets, which are then cooled and collected as individual powder particles. The resulting powder is extremely uniform in size and shape, making it ideal for use in a variety of manufacturing processes.
The MIM Design Guider offers tailored recommendations for each part design that accounts for wall thickness, geometry and other factors. Generally speaking, the minimum wall thickness is 0.050 to 0.250 inch independing on the size of the part, but additional guidance from our experienced engineers is always available.
The MIM process consists of four basic steps: Designing the part, creating the powder formulation, injection molding, and finishing/secondary operations. The MIM Design Guider will help you understand and optimize each step of the process so that you can create a part that is perfect for your application.
It depends on the material used to make the MIM part. Some materials, such as stainless steel or low-carbon steels are magnetic while other materials such as aluminum, cobalt chrome and some titanium alloys are not magnetic. The MIM Design Guider tool can help you select an appropriate material for your application which may be nonmagnetic depending on your requirements.
The price of MIM parts depends on a variety of factors such as material, geometry, size and quantity. Using the MIM Design Guider can help you optimize your design to reduce the cost of your parts. Additionally, MIMA works with many qualified suppliers that can provide competitive pricing for your parts.

The cost of MIM feedstock can vary depending on the type and quantity of alloys used, as well as other factors. However, by utilizing the MIM Design Guider tool, you can optimize your design to reduce the amount of material required, resulting in a more cost-effective solution. Additionally, the MIM Design Guider tool can help you identify potential savings opportunities that might not have been visible during the design process.

MIM binders are composed of polymers, waxes, and lubricants to help the powdered metal particles stick together for injection molding. The binder must be strong enough to hold the shape of the part during injection without breaking down or cracking during cooling. The material also must be able to release from the part after solidification without leaving residue in the final product.
Sintering is the process used in metal injection molding (MIM) to bond the metal powder particles together and form a solid part. During sintering, heat and pressure are applied to the metal powder and each particle melts into its neighbors to form a coherent mass of metal. The MIM Design Guider can help you optimize your sintering parameters for maximum performance and cost efficiency.
When designing parts for injection molding, there are some important guidelines to consider. The most important guideline is to optimize the design for injection molding, which includes limiting the number of cavities and avoiding sharp corners or other features that may cause part defects in metal injection molding. Additionally, engineers should consider the part geometry (length/width ratio), wall thickness uniformity, draft angles to aid in part ejection, and gate sizes to ensure adequate melt flow. Finally, designers must also consider the necessary size of sprue, runners, cores and gating systems
Choosing the right metal for injection molding is an important part of the design process. The MIM Design Guider can help you quickly and easily identify the best metal based on your project requirements, such as strength, cost, and formability. Our tool will generate a recommended list of metals that meet your specific criteria so you can make an informed decision.
The best metal for injection molding depends on your specific product and requirements. MIMA’s Design Guider can help you determine which metal is best for your part as it evaluates each metal in terms of physical properties, production costs, and post-molding performance considerations. With the Design Guider, you can quickly compare and select the best metal to suit your needs.

MIM process offers many advantages over traditional metalworking processes such as cost reduction, reduced lead times, improved part quality and greater design freedom. By using the MIM Design Guider, engineers and designers can optimize their part designs for maximum performance when manufactured through metal injection molding. Additionally, the online tool can help identify potential problems before the parts are even made, saving time and money in the long run.

Yes, titanium is one of the most commonly used metals for metal injection molding. The MIM Design Guider will help you to understand how to design a part that can be injection molded in titanium. Our tool provides guidance on design parameters, part geometry and metallurgy that ensure your parts are optimized for the process so that they can be injection molded with high accuracy and repeatability.
MIM analysis technology is a suite of tools developed by the Metal Injection Molding Association (MIMA) that helps engineers and designers optimize the design of parts for metal injection molding. The MIM Design Guider provides users with detailed simulations and reports that help identify design flaws before the product even enters production. It also provides recommendations on how to optimize certain features in order to reduce manufacturing costs, improve part strength, reduce porosity, and much more. With this powerful tool, you’ll now have all the information you need to make an informed decision about your part’s design.
The Metal Injection Molding (MIM) process is different from traditional casting because it uses a mixture of metal powder and polymeric binder, which, when heated and compressed, forms the desired part. MIM offers many advantages such as high repeatability and low costs in comparison to other methods like die-casting. With the help of the MIM Design Guider you can optimize your parts design taking into account all parameters associated with the MIM manufacturing process.
CNC stands for Computer Numerical Control and is a machining process used to create parts from solid metal blanks. MIM stands for Metal Injection Molding, which is a manufacturing process used for high-volume production of complex parts with tight tolerances, made from metal powders. The MIM Design Guider can help you optimize the design of your parts when using the MIM process.
MIM parts are components manufactured using the metal injection molding process. This process involves the use of thermoplastic binders to shape powdered metals into complex and precise shapes. With the MIM Design Guider, engineers and designers can ensure that their parts are optimized for composition, geometry, tooling, and other design considerations to guarantee quality and cost-efficiency when manufacturing with MIM technology.

Metal Injection Molding (MIM) is a specific type of powder metallurgy. MIM uses a higher percentage of feedstock material, which results in parts with greater strength and denser net shapes than those produced through traditional powder metallurgy techniques. With the MIM Design Guider, you can leverage the benefits of MIM to design robust parts that are both strong and cost-effective.

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