ISO 9001
ISO 14001
IATF16949
ISO 9001
ISO 14001
IATF16949
July 14, 2025
Aluminum die casting is known for producing high-precision parts with excellent mechanical properties. However, like any manufacturing process, it is prone to certain defects if not properly controlled. At Dongguan Yuhui Die Casting, we have over 27 years of expertise in minimizing defects through advanced process control, precision mold design, and strict quality management.
In this article, we explore the most common aluminum die casting defects, their causes, and how we prevent them.
What It Is: Small holes or cavities within the casting caused by trapped gas or improper solidification.
Causes:
Air trapped during injection
Excessive moisture in the mold
Inadequate venting
Uneven cooling rates
Prevention Strategies:
Use vacuum-assisted die casting (vacuum die casting)
Optimize die design and vent placement
Use dry and preheated molds
Control injection speed and pressure
At Yuhui, we use simulation tools like Moldflow during Mold Manufacturing to optimize venting and gate design, reducing internal porosity by over 80%.
What It Is: Visible lines or weak spots on the surface caused by two or more molten metal fronts failing to fuse properly.
Causes:
Low metal temperature
Slow injection speed
Poor gate design
Prevention Strategies:
Increase melt and die temperature to ~680°C
Adjust injection parameters to ensure smooth flow
Redesign gates and runners to improve metal fluidity
Our engineering team uses CAE flow simulation to redesign dies when cold shut is detected during prototyping.
What It Is: Excess metal that leaks out of the mold parting line or ejector pin area.
Causes:
Excessive injection pressure
Poorly fitted or worn die surfaces
Low clamp force
Prevention Strategies:
Maintain die integrity with regular maintenance
Match injection pressure to machine clamping force
Use high-precision die casting machines
At Yuhui, our machines range from 88T to 2000T. Each project is matched with appropriate tonnage to ensure optimal Die Casting conditions and minimal flash.
What It Is: Fractures that occur during the solidification phase due to internal stress.
Causes:
Poor die temperature control
Alloy composition imbalance
Rapid cooling in thick-to-thin transitions
Prevention Strategies:
Use proper mold temperature control (typically 180°C to 250°C)
Ensure consistent wall thickness in part design
Select alloys with better hot cracking resistance
We collaborate with customers during Product Design phase to avoid hot-spot and thick-section risks.
What It Is: Incomplete filling of the mold resulting in missing or thin sections.
Causes:
Low melt temperature
Insufficient injection speed or pressure
Narrow gating system
Prevention Strategies:
Maintain melt temperature at 660–700°C
Increase injection speed or pressure
Optimize runner and gate design
We test all tooling through sampling before mass production, and our misrun defect rate is less than 0.2% thanks to our precision die setup and pre-production trials.
What It Is: Surface indentations that occur in thick sections due to uneven cooling or shrinkage.
Causes:
Uneven wall thickness
Poor die cooling system
Inadequate holding pressure during solidification
Prevention Strategies:
Maintain consistent wall thickness during design
Improve die cooling channel layout
Apply optimal holding pressure
Our expert mold team integrates optimized cooling channels in every die to ensure balanced solidification and cosmetic consistency.
What It Is: Raised areas or bubbles on the casting surface caused by trapped gas or steam.
Causes:
Moisture in die cavity
Improper lubricant usage
Overheating during powder coating or baking
Prevention Strategies:
Preheat and dry dies thoroughly
Use controlled amount of release agent
Monitor post-processing temperatures
For high-demand surface finishing, we offer Surface Treatment services with temperature and process control to eliminate blistering risks.
Our quality control system includes:
100% visual inspection
CMM measurements with accuracy up to ±0.005 mm
Real-time process monitoring
ISO 9001:2015 and IATF 16949 certified workflow
We maintain an internal defect rate below 0.5%, far exceeding industry standards.
Explore our About Us page for more information on our equipment, certifications, and manufacturing standards.
With over 27 years of experience, a 30,000 m² facility, and advanced equipment, Yuhui Die Casting helps clients reduce costs and improve part reliability by proactively eliminating casting defects.
Latest News
Jul. 14, 2025
Common Aluminum Die Casting Defects and How to Prevent Them
Aluminum die casting is known for producing high-precision parts with excellent mechanical properties. However, like any manufacturing process, it is prone to certain defects if not properly controlled.
Read More
Jul. 14, 2025
What is Aluminum Die Casting? Process, Benefits & Applications
Aluminum die casting is a highly efficient manufacturing process that produces precise, complex metal parts with excellent surface quality. At Dongguan Yuhui Die Casting, we specialize in precision aluminum die casting, serving industries such as automotive, aerospace, and telecommunications for over 27 years.
Read MoreSmall Molded Parts with in Days
Our complete CNC aluminum service will accompany your aluminum machining project from the prototype construction to the end aluminum parts manufacturing.
Get a Quote
Eight Processes
High-accuracy aluminum and zinc alloy parts produced with state-of-the-art die casting machines ranging from 88T to 2000T.
Read More
With machines from 88T to 2000T, we produce high-accuracy aluminum and zinc alloy parts efficiently.
Read More
Over 50 CNC machines, including 3-axis, 4-axis, and 5-axis, deliver precise and efficient machining for complex components.
Read More
A combination of manual and automated deburring techniques ensures smooth, defect-free surfaces for optimal performance.
Read More
Post-casting reshaping and alignment guarantee dimensional accuracy and structural integrity.
Read More
Comprehensive finishing solutions, including powder coating, spray painting, and UV coating, ensure superior durability and aesthetics.
Read More
Get in Touch
If you cannot find a suitable product, please leave a message or contact us. We have a dedicated technical team to serve you.
