What is the Maximum Size of Parts that Can Be Produced by MIM Molding?

Metal Injection Molding (MIM) Technology: Maximum Part Size

Metal Injection Molding (MIM) technology is mainly used for manufacturing small and medium-sized parts, but under certain conditions, larger parts can also be produced. Below is a detailed discussion of the factors influencing the maximum size of MIM parts and the size ranges in practical applications.

Factors Affecting the Size of MIM Molded Parts

1. Injection Molding Equipment Capacity

• Injection Pressure and Capacity: The pressure and capacity of the injection molding equipment determine the maximum size and weight of the parts that can be manufactured. Larger parts require higher injection pressure and greater injection capacity. Small injection machines typically have a clamping force of 20-100 tons and an injection volume ranging from tens to hundreds of grams.

• Mold Size: The design and size of the mold directly affect the maximum size of the part. The mold needs to withstand injection pressure and maintain precision. The mold size for small parts is usually within a range of tens of millimeters, suitable for producing small parts like electronic components and medical devices. The mold size for medium-sized parts is typically between 100-200 millimeters, suitable for tools and mechanical parts.

2. Material Properties

• Shrinkage Rate: Materials undergo significant shrinkage during debinding and sintering, usually between 15% and 25%. This needs to be compensated for during the design phase.

• Flowability: The mixture of metal powder and binder needs to have good flowability to fill all detail areas of the mold. Poor flowability can limit the size and complexity of the parts.

3. Sintering Process

• Sintering Furnace Capacity: The size of the sintering furnace limits the maximum size of parts that can be processed. Larger parts require greater sintering furnace capacity and uniform temperature distribution.

• Deformation Control: Large parts are prone to deformation and internal stress during the sintering process, requiring effective process control to maintain dimensional and shape stability.

4. Design and Manufacturing Tolerances

• Dimensional Accuracy: Maintaining high precision becomes more challenging as part size increases. Large parts usually require stricter tolerance control and post-processing techniques.

• Complexity and Details: Complex details and thin-walled structures on large parts are difficult to maintain during molding and sintering, requiring special design and handling.

5. Economic Viability

• Production Cost: The cost of manufacturing large MIM parts is higher, including mold manufacturing, injection molding equipment, and sintering equipment. The MIM process is more costly in the debinding and sintering stages for large/thick parts, reducing overall cost-effectiveness.

Size Ranges in Practical Applications

Based on the above factors, MIM technology is usually used to manufacture small and medium-sized parts, but there are also applications where larger parts are successfully produced. Below are some size ranges in practical applications:

• Small Parts: Common in electronic components, medical device parts, gears, etc., typically ranging from a few millimeters to tens of millimeters.

• Medium Parts: Used in automotive parts, tools, mechanical parts, etc., typically ranging from tens of millimeters to around 100-200 millimeters.

• Larger Parts: Although rare, MIM can produce parts larger than 200 millimeters through optimized processes and equipment. For example, some special mechanical components and structural parts can reach 300 millimeters or even larger.

Conclusion

The size limitations of the MIM process are influenced by multiple factors, including equipment capacity, material properties, debinding process, sintering process, and economic viability. Most applications focus on small to medium-sized parts, but through process and equipment improvements, the MIM process can also achieve the production of larger parts within a certain range. Specific size limitations need to be evaluated and optimized based on specific processes, equipment, and materials.

If you have specific part or project requirements, it is recommended to work with a professional metal injection molding manufacturer for detailed evaluation and design to ensure size and performance requirements are met.