The yield strength of aluminum refers to the amount of stress it can withstand before permanent deformation. This characteristic depends on factors such as alloy composition, heat treatment, and manufacturing process.
This article will explore the concept of yield strength, compare the yield strength values of different aluminum alloys, and emphasize the importance of yield strength in practical applications.
We will also explore factors that affect yield strength and how to enhance it, to provide valuable insights to help you choose the appropriate aluminum material based on your specific needs.
What is Aluminum Yield Strength?
Yield strength is the amount of stress that aluminum can withstand without permanent deformation.
When aluminum is stressed, it initially deforms elastically, meaning it can return to its original shape once the stress is removed.
However, beyond a certain stress level (yield point), the material begins to deform plastically, and this deformation continues even when the stress is removed.
The stress at which this transition occurs is called the yield strength.
Yield strength is usually measured in megapascals (MPa) or pounds per square inch (psi).
Aluminum Yield Strength Values
The following table lists the inherent yield strength values of pure aluminum and various aluminum alloys in their raw material states, both in MPa (megapascals) and psi (pounds per square inch).
|
Alloy |
Yield Strength (MPa) | Yield Strength (psi) |
| Pure Aluminum | 7 – 14 |
1,015 – 2,030 |
|
1050 (Aluminum 1000 Series) |
20 – 40 | 2,900 – 5,800 |
|
1100 (Aluminum 1000 Series) |
30 – 55 |
4,350 – 7,975 |
| 1200 (Aluminum 1000 Series) | 30 – 50 |
4,350 – 7,250 |
|
2004 (Aluminum 2000 Series) |
50 – 80 | 7,250 – 11,600 |
| 2011 (Aluminum 2000 Series) | 60 – 75 |
8,700 – 10,875 |
|
2014 (Aluminum 2000 Series) |
100 – 130 | 14,500 – 18,850 |
| 2024 (Aluminum 2000 Series) | 200 – 300 |
29,000 – 43,500 |
|
3003 (Aluminum 3000 Series) |
35 – 55 | 5,075 – 7,975 |
| 3004 (Aluminum 3000 Series) | 40 – 60 |
5,800 – 8,700 |
|
3005 (Aluminum 3000 Series) |
40 – 55 | 5,800 – 7,975 |
| 3105 (Aluminum 3000 Series) | 50 – 70 |
7,250 – 10,150 |
|
4032 (Aluminum 4000 Series) |
200 – 300 | 29,000 – 43,500 |
| 4045 (Aluminum 4000 Series) | 150 – 250 |
21,750 – 36,250 |
|
5005 (Aluminum 5000 Series) |
70 – 110 | 10,150 – 16,000 |
| 5052 (Aluminum 5000 Series) | 130 – 180 |
18,850 – 26,100 |
|
5083 (Aluminum 5000 Series) |
180 – 250 | 26,100 – 36,250 |
| 6061 (Aluminum 6000 Series) | 150 – 250 |
21,750 – 36,250 |
|
6063 (Aluminum 6000 Series) |
90 – 130 | 13,050 – 18,850 |
| 6082 (Aluminum 6000 Series) | 200 – 250 |
29,000 – 36,250 |
|
7050 (Aluminum 7000 Series) |
320 – 420 | 46,400 – 60,900 |
| 7075 (Aluminum 7000 Series) | 430 – 500 |
62,350 – 72,500 |
|
7085 (Aluminum 7000 Series) |
450 – 500 | 65,250 – 72,500 |
| 8006 (Aluminum 8000 Series) | 30 – 60 |
4,350 – 8,700 |
|
8011 (Aluminum 8000 Series) |
40 – 70 | 5,800 – 10,150 |
| A206 (Cast Aluminum Alloy) | 150 – 250 |
21,750 – 36,250 |
|
A213 (Cast Aluminum Alloy) |
130 – 170 | 18,850 – 24,650 |
| A319 (Cast Aluminum Alloy) | 160 – 210 |
23,200 – 30,450 |
|
A356 (Cast Aluminum Alloy) |
170 – 230 | 24,650 – 33,350 |
| A357 (Cast Aluminum Alloy) | 170 – 230 |
24,650 – 33,350 |
|
A380 (Cast Aluminum Alloy) |
140 – 190 | 20,300 – 27,550 |
| A383 (Cast Aluminum Alloy) | 120 – 180 |
17,400 – 26,100 |
|
A384 (Cast Aluminum Alloy) |
150 – 200 | 21,750 – 29,000 |
| A390 (Cast Aluminum Alloy) | 280 – 350 |
40,600 – 50,750 |
|
A413 (Cast Aluminum Alloy) |
130 – 170 | 18,850 – 24,650 |
| A414 (Cast Aluminum Alloy) | 150 – 190 |
21,750 – 27,550 |
|
A415 (Cast Aluminum Alloy) |
150 – 190 | 21,750 – 27,550 |
| A440 (Cast Aluminum Alloy) | 160 – 220 |
23,200 – 31,900 |
|
A443 (Cast Aluminum Alloy) |
170 – 230 | 24,650 – 33,350 |
| A444 (Cast Aluminum Alloy) | 150 – 190 |
21,750 – 27,550 |
|
ADC10 (Cast Aluminum Alloy) |
100 – 130 | 14,500 – 18,850 |
| ADC12 (Cast Aluminum Alloy) | 140 – 180 |
20,300 – 26,100 |
|
AlSi7Mg (Cast Aluminum Alloy) |
150 – 200 | 21,750 – 29,000 |
| AlSi9Mg (Cast Aluminum Alloy) | 160 – 210 |
23,200 – 30,450 |
|
AlSi10Mg (Cast Aluminum Alloy) |
170 – 230 | 24,650 – 33,350 |
| AlSi12 (Cast Aluminum Alloy) | 180 – 230 |
26,100 – 33,350 |
|
AlSi14 (Cast Aluminum Alloy) |
190 – 250 | 27,550 – 36,250 |
| AlSi15 (Cast Aluminum Alloy) | 200 – 270 |
29,000 – 39,150 |
|
AlSi16 (Cast Aluminum Alloy) |
210 – 280 | 30,450 – 40,600 |
| AlSi18 (Cast Aluminum Alloy) | 220 – 290 |
31,900 – 42,050 |
|
AlSi2Cu (Cast Aluminum Alloy) |
230 – 290 | 33,350 – 42,050 |
| AlSi5Cu3 (Cast Aluminum Alloy) | 240 – 300 |
34,800 – 43,500 |
|
AlSi8Cu3 (Cast Aluminum Alloy) |
250 – 330 | 36,250 – 47,850 |
| AlSi9Cu3 (Cast Aluminum Alloy) | 260 – 350 |
37,700 – 50,750 |
How to Test Aluminum Yield Strength
The following are the most commonly used yield strength testing methods:
Tensile Testing
The most common method for determining yield strength is the tensile test. In this test, an aluminum sample is stretched until it deforms.
Yield strength is determined by the point at which the material changes from elastic (reversible) deformation to plastic (permanent) deformation.
Offset Method
The 0.2% offset method is suitable for alloys without an obvious yield point.
In this method, the yield strength is defined as the stress at which the material is subjected to a permanent strain of 0.2%, which is ideal for alloys with a gradual transition from elastic to plastic deformation.
Factors Affecting Aluminum Yield Strength
The yield strength of aluminum is influenced by several factors, including alloy composition, heat treatment, and manufacturing process, each plays a critical role in its overall strength and properties.
Alloy Composition
Alloying elements such as copper and magnesium directly affect the yield strength of aluminum.
Copper increases yield strength by forming a solid solution, but reduces corrosion resistance.
Magnesium increases the yield strength of aluminum by forming hard precipitates, which improves the structure and stress resistance of aluminum.
Heat Treatment
Heat treatments such as solid solutions and aging treatments can increase the yield strength of aluminum by changing its microstructure. These processes can form hard precipitates that resist deformation.
Conversely, annealing can soften aluminum and improve its formability by increasing its grain size.
Processing Method
Manufacturing processes can affect the grain structure of aluminum.
Forging makes grains neat and prevents deformation, thereby increasing the yield strength.
However, traditional aluminum casting methods such as sand casting or die casting can lead to porosity and irregular grains during production, which will reduce yield strength.
Importance of Yield Strength in Practical Applications
Aluminum’s yield strength is critical to its performance in various industries.
Here are the reasons why yield strength is important in practical applications:
Structural Integrity
Yield strength ensures that aluminum components can withstand mechanical loads without permanent deformation.
This is critical in industries such as aerospace and automotive, where safety and reliability depend on the material’s ability to maintain structural integrity under stress.
Strength-to-Weight Ratio
In applications such as electronics and consumer goods, high yield strength allows for the use of lighter and more durable materials.
Products such as laptops, smartphones, and home appliances can be made thinner and lighter without sacrificing strength, making them more portable and energy-efficient.
Corrosion Resistance
In industries such as construction or marine, aluminum components are exposed to extreme conditions.
High yield strength ensures that these components remain functional and intact even in high-stress, corrosive, or high-temperature environments.
Fatigue Resistance
In applications that are subjected to repeated stress, such as vehicle suspensions or sports equipment, high yield strength helps prevent fatigue.
This allows aluminum to withstand cyclic loads without cracking or deforming over time.
How Does CEX Improve the Yield Strength of Aluminum
Advanced technology is essential, at CEX Casting, we use patented squeeze casting technology to improve the yield strength of aluminum.
Squeeze Casting
Squeeze casting reduces porosity and ensures a dense internal structure by controlled cooling.
This eliminates weak points and enhances the deformation resistance.
The high pressure during squeeze casting can refine the grain structure and align it along the flow direction, thereby improving the mechanical properties in that direction.
Squeezing castings can undergo T6 heat treatment, which involves a solid solution followed by artificial aging.
This process can improve the yield strength and hardness, thereby further optimizing the mechanical properties of castings.
The following table shows the heat treatment methods suitable for different aluminum casting processes:
|
Aluminum Alloy Casting Process |
Suitable Heat Treatment Method |
| Low-Pressure Die Casting |
T5, T6 |
|
Sand Casting |
T4, T6 |
|
Squeeze Casting |
T6 |
| High-Pressure Die Casting |
not recommend |
| Permanent Mold Casting (Steel Mold Casting) |
not recommend |
CEX Squeeze Casting Equipment
CEX’s Successful Cases
● Tensile Strength: 300MPa
● Yield Strength: 260MPa
● Hardness: 92Hb
● Tensile Strength: 300MPa
● Yield Strength: 250MPa
● Hardness: 92Hb
● Tensile Strength: 300MPa
● Yield Strength: 260MPa
● Hardness: 90Hb
Conclusion
The yield strength determines the ability of aluminum to withstand stress without permanent deformation which is a key factor in its performance and reliability.
For industries such as automotive, aerospace, and construction, yield strength is important as the materials must withstand high stresses while maintaining their structural integrity.
At CEX Casting, we combine advanced squeeze casting technology with T6 heat treatment to improve the yield strength of aluminum castings.
This ensures that castings come with excellent yield strength for demanding applications.
Contact us today to learn how our solutions can help you create stronger and more reliable products.