Introduction
When developing metal components, engineers are often faced with a difficult balance: achieving high mechanical strength, complex part geometry, and reasonable manufacturing costs at the same time.
Traditional casting processes provide great flexibility in producing complex shapes, but they also have limitations. Problems such as gas porosity, shrinkage defects, cold shuts, and inconsistent material properties can affect the final performance of the component, especially in applications where strength and reliability are critical.
To overcome these challenges, squeeze casting was developed as a process that combines the advantages of casting and forging. By applying high pressure during the solidification process, squeeze casting helps produce denser components with improved mechanical properties and reduced internal defects.
At Raidy Mold Manufacturer, we work closely with customers to solve challenging tooling and manufacturing requirements. With extensive experience in die casting mold design and manufacturing, we help engineers develop high-performance metal components with better quality, stability, and production efficiency.
What Is Squeeze Casting?
Squeeze casting is a metal manufacturing process that combines the principles of casting and forging to produce high-performance components. Unlike conventional casting methods, where molten metal solidifies without continuous pressure, squeeze casting applies high pressure during the solidification stage. This additional pressure helps reduce internal porosity, improve material density, and enhance the mechanical properties of the final part. For manufacturers producing aluminum components that require higher strength, better reliability, and tighter quality control, squeeze casting provides an effective solution between traditional casting and forging processes.
What Is the Purpose of Squeeze Casting?
The main purpose of squeeze casting is to improve the quality and performance of cast metal components by applying high pressure during the solidification process. Compared with conventional casting methods, squeeze casting helps reduce internal porosity, minimize shrinkage defects, and produce parts with higher density and better mechanical properties.
For manufacturers producing aluminum components that require high strength and reliability, squeeze casting provides a way to achieve casting flexibility while approaching the performance level of forged parts. This makes it suitable for applications such as automotive structural components, EV parts, and other load-bearing components.
From a tooling perspective, squeeze casting also places higher requirements on mold design and manufacturing. The mold must withstand repeated high-pressure and thermal cycling conditions while maintaining dimensional accuracy and long service life. Therefore, a well-designed and precisely manufactured mold plays an important role in ensuring stable production and consistent part quality.
How Squeeze Pins Reduce Shrinkage Porosity in Die Casting
The Cause of Shrinkage Porosity
In aluminum die casting, shrinkage porosity is one of the common internal defects that can affect the quality and reliability of cast components. It often occurs in areas with thicker wall sections, local heat concentration areas, or around features such as threaded holes, where sufficient feeding during solidification is difficult to achieve.
Under normal conditions, the density of molten aluminum is approximately 2.6 g/cm³, while the density of solidified aluminum is approximately 2.7 g/cm³. During the solidification process, aluminum naturally undergoes volume shrinkage and requires continuous feeding of molten metal to compensate for this contraction.
However, in the actual die casting process, the outer areas of the casting usually solidify first. Once a solidified shell forms, the casting pressure becomes less effective in transferring pressure to the internal thick-wall areas. As a result, these areas may not receive sufficient molten aluminum replenishment during solidification.
This insufficient feeding can create a localized vacuum-like tearing condition inside the casting, eventually leading to the formation of shrinkage porosity.
How Local Squeeze Pins Improve Shrinkage Porosity
To solve shrinkage problems in thick-wall areas, a local pressure die casting process using squeeze pins can be applied.
After the molten aluminum fills the mold cavity, a squeeze pin installed in the die applies additional local pressure during the solidification and shrinkage stage. This pressure forces the semi-solid aluminum in the surrounding area to continue feeding the shrinkage zone, reducing the formation of internal voids.
Compared with relying only on the original casting pressure, local squeeze pin technology provides additional pressure directly to areas where feeding is difficult. This makes it especially effective for thick sections, hot spots, and critical areas that require improved internal quality.
Improvement of Internal Structure After Squeeze Pin Application
The function of a squeeze pin is not only to reduce shrinkage porosity but also to improve the internal structure of the casting.
Through localized pressure during solidification, internal voids caused by metal shrinkage can be compressed and reduced. At the microscopic level, the material structure becomes denser and more compact, improving the overall internal quality and consistency of the die casting part.
Shrinkage Porosity Improvement Comparison Using Local Squeeze Pins
The following comparison shows the improvement effect of applying local squeeze pin technology to the threaded hole area of a bracket component.
Without local squeeze pin technology (left image):
Due to insufficient feeding during solidification, shrinkage porosity appears around the thick-wall area near the threaded hole.
With local squeeze pin technology (right image):
By applying additional pressure during the solidification stage, molten aluminum is effectively supplied to the shrinkage area. The shrinkage defect is improved, and the internal structure becomes more compact.
This comparison demonstrates how local squeeze pin design can effectively reduce shrinkage-related defects in critical areas and improve the internal quality stability of aluminum die castings.
The Importance of Squeeze Pin Design in Die Casting Mold Manufacturing
The effectiveness of local squeeze pin technology depends not only on the squeeze pin itself but also on the overall die casting mold design.
During mold development, factors such as the squeeze pin location, diameter, stroke, timing, and installation structure need to be carefully considered according to the part geometry, wall thickness distribution, and potential shrinkage risk areas.
An optimized squeeze pin design can improve feeding performance and casting quality, while an improper design may not achieve the expected results and could affect mold durability and production stability.
As a professional High Pressure Die Casting Mold Manufacturer, Raidy focuses on analyzing potential casting defects during the mold design stage and providing optimized tooling solutions. By combining mold design experience with die casting process knowledge, we help customers improve part quality, reduce production risks, and achieve more stable mass production.
If your aluminum die casting parts have shrinkage porosity issues or challenging thick-wall structures, Raidy’s engineering team can evaluate your part design and recommend suitable mold solutions.
Shrinkage Porosity Prevention by Applying Squeeze Pin Technology
During the development of a bracket die casting part, shrinkage porosity was identified as a potential risk in the threaded hole area. Based on the external defect analysis, the issue was determined to be related to internal hot spots and insufficient feeding during solidification, which could potentially lead to shrinkage cracks and pinhole defects inside the casting.
To prevent this issue before mass production, Raidy performs an early-stage risk assessment during the mold design process. By analyzing the part structure and potential shrinkage areas, our engineering team provides optimization solutions before the mold manufacturing stage.
For this component, the area with a high shrinkage risk was redesigned with a local squeeze pin structure. A squeeze pin was added at the corresponding location on the moving mold side to apply additional pressure during the solidification process.
Through this local pressure solution, the feeding condition in the critical area was improved, effectively preventing shrinkage defects and ensuring better internal quality of the casting part.
Identifying potential casting risks early—before the aluminum die-casting mold is manufactured—is crucial. At Raidy, we combine our practical die-casting experience with expertise in mold design to help clients optimize mold solutions during the early stages of a project; this minimizes the risk of defects, avoids costly mold modifications, and enhances production reliability.
If you are developing a new aluminum alloy die-casting project or encountering issues such as shrinkage porosity during the production of existing parts, our engineering team can evaluate your part designs and provide practical recommendations for mold optimization.
Squeeze Equipment Configuration
To meet different project requirements and production conditions, Raidy can provide customized squeeze equipment configuration solutions for local squeeze pin applications.
The system is designed for independent control of squeeze pins in die casting molds, supporting both automatic and manual operation modes. Under automatic mode, the squeeze system can be synchronized with the die casting machine signal, while squeeze delay time and holding pressure time can be individually adjusted according to process requirements.
The system is equipped with a Mitsubishi PLC control system, allowing all parameters to be easily adjusted through the touchscreen interface. Multiple squeeze channels can be controlled independently, enabling precise pressure management for different areas of the mold.
With adjustable hydraulic pressure up to 21 MPa, pressure monitoring, cooling protection, fault diagnosis, and parameter storage functions, the system ensures stable operation and repeatable squeeze performance during production.
By integrating local squeeze equipment with optimized mold design, Raidy helps customers improve casting quality, reduce shrinkage defects, and achieve more stable die casting production.
FAQ
What is the main purpose of squeeze casting?
The main purpose of squeeze casting is to produce higher-quality metal components with improved strength, reduced shrinkage defects, and better internal structure compared with conventional casting processes.
It is commonly used for aluminum components requiring high reliability, such as automotive structural parts, EV components, and other load-bearing applications.
What causes shrinkage porosity in aluminum die casting?
Shrinkage porosity occurs when molten aluminum cannot sufficiently compensate for volume contraction during solidification.
It commonly appears in thick-wall sections, hot spots, and areas where casting pressure cannot effectively reach during the final stage of solidification.
How do squeeze pins reduce shrinkage porosity?
Squeeze pins apply additional local pressure during the solidification stage. This pressure helps push semi-solid aluminum into areas affected by shrinkage, improving feeding conditions and reducing internal voids.
What factors need to be considered when designing a squeeze pin system?
In some cases, squeeze pin structures can be added or modified depending on the existing mold design, available space, and production requirements.
However, the feasibility needs to be evaluated based on part structure, shrinkage location, and mold construction.
What factors need to be considered when designing a squeeze pin system?
Important factors include:
- Squeeze pin location
- Pin diameter and stroke
- Pressure requirements
- Timing during solidification
- Mold structure and durability
- Cooling and production conditions
Proper design is essential to achieve stable results during mass productio
Does Raidy provide squeeze equipment solutions?
Yes. Raidy can provide customized squeeze equipment configuration solutions according to project requirements.
The system supports automatic and manual operation modes, independent squeeze channel control, adjustable pressure settings, and integration with die casting machine signals to achieve stable local pressure control.
How can Raidy help with my die casting project?
Raidy supports customers from early design evaluation through mold manufacturing.
Our engineering team can help identify potential casting risks, optimize mold structures, and provide solutions for issues such as shrinkage porosity, thick-wall defects, and internal quality problems.
You can send your 2D drawing or 3D model to our engineering team for a professional evaluation.
Conclusion: Optimizing Die Casting Quality Through Advanced Mold Solutions
Squeeze casting and local squeeze pin technology provide effective solutions for improving internal quality, reducing shrinkage porosity, and enhancing the reliability of aluminum die castings. However, achieving consistent results depends not only on the process itself, but also on the accuracy of mold design, tooling structure, and manufacturing experience.
At Raidy Mold Manufacturer, we focus on identifying potential casting risks at the early development stage and providing practical mold optimization solutions before production begins. By combining die casting process knowledge, precision mold manufacturing capabilities, and local squeeze technology, we help customers reduce development risks, improve part quality, and achieve stable mass production.
Whether you are developing a new aluminum die casting component or looking for solutions to existing issues such as shrinkage porosity, internal defects, or challenging thick-wall structures, Raidy’s engineering team can support you from mold design evaluation to final tooling production.
Send us your 2D drawing or 3D model today. Our engineers will evaluate your part requirements and provide a professional die casting mold solution tailored to your project.
