Choosing the right cast aluminum alloy depends on key factors like strength, corrosion resistance, casting compatibility, and heat treatment potential. Some alloys are ideal for structural parts, others for high-volume production or harsh environments. Due to performance and processing vary across different grades, the alloy must be carefully matched to the application’s functional, environmental, and manufacturing requirements.
This article will explore the key advantages of cast aluminum materials, alloy classifications, performance comparisons, grade comparisons, selection factors, and the benefits of heat treatment. Read on to learn how to make an intelligent material choice for your next aluminum casting project.
Key Benefits of Cast Aluminum Materials
High Strength-to-Weight Ratio
Aluminum has a density of about one-third that of steel, but its mechanical properties are still competitive.
This makes aluminum an ideal material for reducing the weight of aluminium die casting components used in vehicles and equipment without sacrificing strength.
It is particularly suitable for automotive and aerospace applications where strength-to-weight ratios are strictly required.
Excellent Corrosion Resistance
Aluminum naturally forms an oxide film that effectively resists corrosion in most environments.
This self-protective barrier reduces the need for coatings or painting, allowing aluminum die casting parts to perform stably in marine, outdoor, and chemical environments for a long time.
High Thermal and Electrical Conductivity
Aluminum alloys have excellent thermal and electrical conductivity, making them ideal for components such as radiators, engine blocks, and electronic housings.
Superior thermal conductivity helps with thermal management, ensures stable electrical performance, and reduces the risk of overheating in high-load systems.
Excellent Casting Performance
Aluminum alloys have a low melting point (about 660°C), good fluidity, and low shrinkage.
These physical properties enable them to quickly fill complex areas of die casting molds in a molten state, making them particularly suitable for thin-walled and complex aluminum die casting products.
Recyclability and Environmental Friendliness
Aluminum materials are 100% recyclable and can maintain their original properties after multiple cycles.
Compared with primary aluminum production, recycled aluminum requires very little energy, making it an environmentally friendly and economical material of choice for manufacturers focused on sustainable development.
Classification of Aluminum Casting Materials
Classification by Alloy Type
Al-Si Alloy
Al-Si alloys such as A356.0, A357.0, 319.0, and 413.0 have high silicon content, excellent fluidity, low shrinkage, and good wear resistance.
They are widely used in the automotive and general engineering fields and are suitable for structural parts that require dimensional accuracy and mechanical strength.
Al-Si-Cu Alloy
Al-Si-Cu alloys such as A380.0, A383.0, ADC12, and 413.0 have copper and silicon added to them, and have high castability and thermal conductivity.
They are commonly used in electronic housings and automotive parts, and are very suitable for scenarios with high requirements for dimensional accuracy, airtightness, and mass production efficiency.
Al-Cu Alloy
Al-Cu alloys such as 206.0 and 214.0 have high copper content, which gives them excellent strength and high temperature resistance.
They are widely used in aerospace and military parts, but have high requirements for process control and require heat treatment after casting.
Al‑Mg Alloys
Al‑Mg alloys such as 535.0 and 519.0 are suitable for parts exposed to seawater or corrosive environments.
The magnesium element provides excellent corrosion resistance, and the mechanical properties are sufficient to support long-term use in marine equipment, outdoor lighting, structural parts, etc.
Al‑Zn Alloys
Al‑Zn alloys such as 713.0 and 712.0, zinc-rich alloys, have very high strength and hardness and are suitable for heavy industry.
However, their castability and corrosion resistance are poor, and they are only suitable for niche applications with extreme requirements for mechanical properties.
Classification by Casting Process
Die Casting
A380.0, A383.0, ADC12, 384.0, and 390.0 are suitable for high-efficiency mass production using the die casting process.
These alloys have good filling capacity, dimensional accuracy, and surface finish, and are often used in electronic products, automotive parts, and consumer electronics housings.
Sand Casting
A356.0, 319.0, 535.0, and 206.0 are suitable for large-size, thick-walled, or low-volume sand casting production.
The mold has a low cost and flexible design, and is mostly used for sample trial production, engines, pump casings, and structural parts.
Permanent Mold Casting
A357.0, C355.0, 319.0, and 443.0 are suitable for permanent mold casting.
This process can produce castings with high density and excellent mechanical properties, and the surface quality and dimensional consistency are better than sand casting.
Suitable for medium-volume production and application scenarios that focus on strength, appearance, and repeatability.
Investment Casting
AlSi10Mg, A356.0, A357.0, and 535.0 are suitable for investment casting. This process can manufacture complex and high-precision parts.
It is widely used in the aviation, defense, and medical industries, especially for occasions with high surface quality and tolerance requirements.
Low-Pressure Casting
A356.0, A357.0, and 319.0 are the preferred materials for low-pressure casting. This process can produce dense, low-porosity parts.
Suitable for use in key structural parts, with high consistency and low defect rate, commonly used in load-bearing parts such as automobile chassis and suspension systems.
Squeeze Casting
Common materials for squeeze casting include A356.0, A357.0, 206.0, AlSi10Mg, etc.
This process combines the advantages of casting and forging to produce high-density, high-strength parts, and is often used in parts with extremely high performance requirements, such as automobile control arms and aviation structural parts.
Squeeze Casting Workshop at CEX Casting
Common Cast Aluminum Alloy Performance Comparison Table
|
Alloy |
Composition | Strength (MPa) | Heat Treatable |
|
A356 |
Al‑Si‑Mg | 250–320 | Yes |
| A360 | Al‑Si‑Mg‑Cu | 240–300 |
Yes |
|
A380 |
Al‑Si‑Cu | 170–230 | No |
| A383 | Al‑Si‑Cu | 180–240 |
No |
|
319 |
Al‑Si‑Cu | 200–250 | No |
| 413 | Al‑Si‑Cu‑Mg | 240–280 |
No |
|
206.0 |
Al‑Cu | 320–390 | Yes |
| ADC12 | Al‑Si‑Cu | 160–240 |
No |
|
C355/A357 |
Al‑Si‑Mg‑Cu | 300–350 |
Yes |
| 535.0 | Al‑Mg | 200–260 |
No |
Common Cast Aluminum Alloy Grades Comparison Table
|
USA (AA/ASTM) |
Japan (JIS) | Europe (EN AC) | China (GB/ZL) |
| A356 | AC4CH | EN AC‑43000 |
ZL101 |
|
A360 |
AC4D | EN AC‑43100 | ZL103 |
| A380 | ADC10 | EN AC‑46500 |
ZL104 |
|
A383 |
ADC12 | EN AC‑46000 | ZL108 |
| 319 | ADC11 | EN AC‑42000 |
ZL112 |
|
413 |
AC9B | EN AC‑42100 | ZL113 |
| A357 | AC4CN | EN AC‑43300 |
ZL111 |
|
206.0 |
— | EN AC‑51200 | ZL201 |
| C355 | AC4C | EN AC‑43200 |
ZL109 |
|
535.0 |
— | EN AC‑51100 | ZL302 |
| AlSi10Mg | — | EN AC‑43000 |
ZL101A |
Key Factors for Aluminum Alloy Selection
Mechanical Performance Requirements
Aluminum alloys vary greatly in strength, ductility, and fatigue life. If used for load-bearing or structural parts, high-strength, heat-treatable alloys such as A357 and 206.0 should be selected.
If only for shells or non-load-bearing parts, alloys with good castability and low cost, such as A380 and ADC12, can be selected.
Corrosion Resistance
Al-Mg alloys such as 535.0 and 519.0 perform well in marine, outdoor, and chemical environments and are suitable for long-term exposure.
Although Al-Cu alloys have high strength, they are prone to corrosion and need to be anodized or sprayed to enhance durability.
Machinability and Surface Quality
High-silicon alloys such as A380 castings have fine surfaces and high casting precision, but the tool wear is large during machining, and the machining efficiency is low.
Al-Mg alloys such as 535.0 can be processed smoothly and are suitable for precision machining, but the surface roughness is slightly higher and requires appropriate post-treatment.
Heat Treatment Adaptability
If it is necessary to subsequently improve strength or fatigue resistance, heat-treatable alloys such as A356-T6 and C355-T6 should be selected.
High silicon alloys such as A380 and ADC12 cannot be strengthened by heat treatment and are suitable for occasions with low strength requirements.
Production and Cost Budget
Sand mold or gravity casting is recommended for small batches in the initial stage, with low mold investment and flexible debugging.
Die casting or metal mold casting is recommended for mass production, and standardized alloys such as A380 and ADC12 can significantly reduce unit costs and improve consistency.
Process Adaptability
Different aluminum alloys have different performances in various casting processes. A380 and A383 have strong fluidity and are suitable for die casting of complex shapes.
A356 and A357 have low thermal cracking tendency and are suitable for low-pressure, sand mold, or squeeze casting.
Cast aluminum alloys with matching processes must be selected according to part structure and performance requirements.
Heat Treatment and Performance Improvement
Common Heat Treatment Types
Common heat treatment methods for aluminum castings include:
-
T4: Natural aging after solution treatment to improve ductility and machinability.
-
T5: Direct artificial aging after casting, suitable for occasions that do not require high strength but require dimensional stability.
-
T6: Solution treatment followed by artificial aging is the most commonly used strengthening solution, which significantly improves strength and fatigue performance.
-
T7: Overaging based on T6, sacrificing some strength in exchange for better corrosion resistance and dimensional stability, often used in high-temperature environments.
Applicable Alloys
Aluminum alloys with heat treatment capabilities mainly include Al‑Si‑Mg and Al‑Cu systems. Common ones include:
-
A356-T6: Widely used in wheels, engine housings, etc., with excellent comprehensive performance.
-
A357-T6: Higher mechanical properties, suitable for aviation and heavy-duty structural parts.
-
C355-T6: Combines strength and toughness, suitable for applications requiring impact resistance and weldability.
These alloys show higher tensile strength (up to 300–350 MPa), good ductility, and fatigue life after heat treatment.
Advantages of Heat Treatment
Heat treatment of aluminum alloys can increase strength by 20–35%, allowing them to meet higher mechanical load and fatigue requirements.
At the same time, T6 or T7 states can also significantly enhance impact resistance and wear resistance, extending service life.
For key application scenarios such as automotive chassis, aerospace structural parts, and safety shells, heat treatment is a key step to achieve performance and stability.
Heat Treatment Equipment at CEX Casting
Recommended Cast Aluminum Alloys by Application
|
Application |
Recommended Alloys | Reason |
|
Structural Parts |
A357, 206.0, C355 | High strength and heat-treatable |
| Automotive Components | A356, A360, 319, A383 |
Lightweight, cost-effective, good castability |
|
Aerospace Components |
206.0, A357, C355 | Excellent strength-to-weight, fatigue resistance |
| Electronics & Housings | ADC12, A380, 319 |
Precision casting, thermal conductivity |
|
Marine/Corrosive Use |
535.0, 519.0 | Strong corrosion resistance |
| Thin-Walled & Complex Shapes | AlSi10Mg, A413, A383 |
High fluidity, detail accuracy |
|
High-Volume Production |
A380, ADC12, 319 | Optimized for high-pressure die casting |
| Prototyping & Small Runs | A356, A357 |
Flexible, low tooling cost |
CEX Casting’s Alloy Expertise and Support Services
Customized Alloy Selection Guidance
CEX Casting provides international buyers with alloy recommendations based on part function, casting method, and mechanical requirements.
We analyze customer drawings and provide material solutions that balance strength, castability, and cost to ensure performance and production efficiency.
Material Quality Inspection Laboratory
Our in-house laboratory can perform comprehensive material testing, including tensile strength, yield strength, elongation, hardness, and chemical composition analysis.
Each batch of materials is strictly tested to ensure that it meets international standards and customer technical requirements.
Conclusion
Choosing the right cast aluminum alloy is the key to achieving the best balance between strength, corrosion resistance, castability, and cost control.
As a professional aluminium alloy die casting supplier in China, CEX Casting provides professional alloy selection and comprehensive material testing services to ensure that every aluminum die casting meets performance expectations.
Contact us now to find the most suitable material solution for your next aluminum alloy casting project.