A356 aluminum alloy is generally not suitable for high pressure die casting. Its low iron content leads to severe sticking and mold damage. The high shrinkage during solidification makes it prone to porosity and dimensional instability. In addition, under rapid cooling conditions, A356 has a high tendency to hot cracking, making it difficult to maintain consistent quality in die casting products.
This article will introduce the basic properties of A356, the main problems in A356 die casting aluminum, the die casting process suitable for A356, the squeeze casting technology of CEX, and commonly used alloys in traditional aluminium alloy die casting. Let’s go ahead and read on to find out.
A356 Aluminum Alloy Properties
Chemical Composition
A356 aluminum alloy contains about 7% silicon and 0.3% magnesium, but the iron content is extremely low; this gives A356 excellent corrosion resistance.
However, due to the low iron content, it is not suitable for high pressure die casting environments.
Casting Suitability
A356 has high strength and good elongation after T6 heat treatment and performs well in sand casting and metal mold casting.
However, its characteristics are more suited for slow solidification processes, and hard to cope with the rapid cooling and filling speed in the conventional die casting process.
Main Problems of A356 in High Pressure Die Casting
Severe Sticking
Due to the low iron content, A356 lacks an iron-rich phase protective layer, and molten aluminum easily adheres to the mold surface.
This leads to increased mold wear, frequent mold replacement, and high maintenance costs.
High Defect Rate
A356 has large solidification shrinkage and is prone to defects such as pores and thermal cracking. At the same time, its mechanical properties are extremely sensitive to process fluctuations.
This makes A356 difficult to ensure the strength and dimensional consistency of die casting parts.
High Operation Difficulty
To reduce the risk of defects, A356 die casting requires strict control over parameters such as mold temperature and filling speed.
Therefore, the process of debugging is difficult, production flexibility is poor, and the overall die casting process becomes more complicated.
High Cost
The combination of short mold life, low yield rates, and low production efficiency significantly increases the cost of aluminium alloy die casting with A356.
As a result, A356 is less suitable for mass production and lacks cost competitiveness for die casting manufacturers.
Casting Processes Suitable for A356 Aluminum Alloy
Sand Casting
Ideal for A356, sand casting’s slow cooling minimizes thermal cracking and internal stress. It suits complex or large aluminum casting parts where precision is less critical.
Permanent Mold Casting
This method offers better surface finish and dimensional accuracy than sand casting. For A356, it reduces porosity and cracking, making it a stable alternative to high pressure die casting.
Low Pressure Casting (LPDC)
LPDC is highly compatible with A356, producing dense, defect-free aluminium casting components by controlling flow and cooling more effectively than the traditional die casting method.
Squeeze Casting by CEX Casting
Process Principle
CEX Casting’s patented squeeze casting process pours molten A356 aluminum into a preheated mold, then applies high pressure during solidification.
This minimizes turbulence and porosity, producing dense, high-strength die casting components with superior consistency compared to traditional high pressure die casting.
Why Squeeze Casting Works for A356
Squeeze casting effectively eliminates traditional A356 die casting issues like sticking and hot cracking.
By optimizing metal flow and cooling, it produces aluminium casting components with fine-grain structure and low porosity.
After T6 heat treatment, parts achieve excellent strength and durability, meeting the demands of high-performance applications.
Testing Report
We have conducted comprehensive mechanical property tests on our A356 squeeze castings. Below is a detailed test report showing the superior properties of our die casting products.
Common Alloys for Traditional Aluminum Die Casting
A380
A380 is the most widely used alloy for traditional aluminium alloy die casting. It offers excellent fluidity, low shrinkage, and easy mold release.
With an ideal balance between strength, cost, and efficiency, it is commonly used in the automotive and electronics industries.
ADC12
ADC12 offers excellent castability, corrosion resistance, and mechanical strength.
It is especially suited for high-speed die casting manufacturing, making it a favorite for automotive, consumer electronics, and household appliances.
A360
A360 offers better corrosion resistance and sealing than A380, ideal for harsh environments.
It is widely used in marine, hydraulic, and premium automotive systems due to its strength, light weight, and superior casting performance.
Conclusion
A356 aluminum alloy is fundamentally unsuitable for traditional high pressure die casting.
However, through CEX‘s advanced squeeze casting technology, A356 can achieve excellent mechanical properties and dimensional consistency.
As a leading die casting supplier in China, CEX Casting provides end-to-end services, from mold design to final finishing, for custom die casting parts.
Contact us today to see how our innovative solutions can elevate your next A356 aluminum alloy casting project.