The density of aluminum is a measure of mass per unit volume. At room temperature, the average density of pure aluminum is typically about 2.7 grams per cubic centimeter (g/cm ³). This makes aluminum one of the lightest metals, which is also why aluminum is widely used in the automotive, aerospace, and construction industries. The specific density may vary slightly depending on the purity of the aluminum or whether it is an alloy.
Understanding the density of aluminum is key to understanding its versatility and performance.
Density plays a central role in the application of aluminum, from its standard values to measurement methods, influencing factors, density differences between pure aluminum, alloys, and other metals, as well as its role in casting.
In the following chapters, we will delve into these aspects in depth.
Density of Pure Aluminum and Aluminum Alloys
The density of aluminum varies depending on its grade and alloying elements.
The standard density of pure aluminum is 2.7 g/cm ³, while the density of different alloys may vary slightly.
The following table lists the densities of commonly used aluminum materials:
|
Alloy |
Density (g/cm³) | Density (kg/m³) | Density (lb/in³) |
|
Pure Aluminum |
2.7 | 2700 | 0.0974 |
| 1050 (Aluminum 1000 Series) | 2.71 | 2710 |
0.0982 |
|
1100 (Aluminum 1000 Series) |
2.71 | 2710 | 0.0982 |
|
1200 (Aluminum 1000 Series) |
2.71 | 2710 | 0.0982 |
|
2004 (Aluminum 2000 Series) |
2.85 | 2850 |
0.103 |
| 2011 (Aluminum 2000 Series) | 2.83 | 2830 |
0.102 |
| 2014 (Aluminum 2000 Series) | 2.81 | 2810 |
0.1018 |
|
2024 (Aluminum 2000 Series) |
2.78 | 2780 | 0.1014 |
| 3003 (Aluminum 3000 Series) | 2.73 | 2730 |
0.0988 |
|
3004 (Aluminum 3000 Series) |
2.73 | 2730 | 0.0988 |
| 3005 (Aluminum 3000 Series) | 2.74 | 2740 |
0.0989 |
|
3105 (Aluminum 3000 Series) |
2.74 | 2740 | 0.099 |
| 4032 (Aluminum 4000 Series) | 2.68 | 2680 |
0.0972 |
|
4045 (Aluminum 4000 Series) |
2.68 | 2680 | 0.0972 |
| 5005 (Aluminum 5000 Series) | 2.66 | 2660 |
0.0966 |
|
5052 (Aluminum 5000 Series) |
2.68 | 2680 | 0.0972 |
| 5083 (Aluminum 5000 Series) | 2.66 | 2660 |
0.0966 |
|
6061 (Aluminum 6000 Series) |
2.7 | 2700 | 0.0974 |
| 6063 (Aluminum 6000 Series) | 2.7 | 2700 |
0.0974 |
|
6082 (Aluminum 6000 Series) |
2.7 | 2700 | 0.0974 |
| 7050 (Aluminum 7000 Series) | 2.81 | 2810 |
0.1018 |
|
7075 (Aluminum 7000 Series) |
2.81 | 2810 | 0.1018 |
| 7085 (Aluminum 7000 Series) | 2.82 | 2820 |
0.1019 |
|
8006 (Aluminum 8000 Series) |
2.7 | 2700 | 0.0974 |
| 8011 (Aluminum 8000 Series) | 2.7 | 2700 |
0.0974 |
|
A206 (Cast Aluminum Alloy) |
2.83 | 2830 | 0.102 |
| A213 (Cast Aluminum Alloy) | 2.7 | 2700 |
0.0974 |
|
A319 (Cast Aluminum Alloy) |
2.74 | 2740 | 0.0989 |
| A356 (Cast Aluminum Alloy) | 2.68 | 2680 |
0.0972 |
|
A357 (Cast Aluminum Alloy) |
2.68 | 2680 | 0.0972 |
| A380 (Cast Aluminum Alloy) | 2.75 | 2750 |
0.0995 |
|
A383 (Cast Aluminum Alloy) |
2.76 | 2760 | 0.0996 |
| A384 (Cast Aluminum Alloy) | 2.75 | 2750 |
0.0995 |
|
A390 (Cast Aluminum Alloy) |
2.85 | 2850 | 0.103 |
| A413 (Cast Aluminum Alloy) | 2.7 | 2700 |
0.0974 |
|
A414 (Cast Aluminum Alloy) |
2.72 | 2720 | 0.0983 |
| A415 (Cast Aluminum Alloy) | 2.68 | 2680 |
0.0972 |
|
A440 (Cast Aluminum Alloy) |
2.73 | 2730 | 0.0987 |
| A443 (Cast Aluminum Alloy) | 2.76 | 2760 |
0.0996 |
|
A444 (Cast Aluminum Alloy) |
2.72 | 2720 | 0.0983 |
| ADC10 (Cast Aluminum Alloy) | 2.7 | 2700 |
0.0974 |
|
ADC12 (Cast Aluminum Alloy) |
2.7 | 2700 | 0.0974 |
| AlSi7Mg (Cast Aluminum Alloy) | 2.68 | 2680 |
0.0972 |
|
AlSi9Mg (Cast Aluminum Alloy) |
2.69 | 2690 | 0.0973 |
| AlSi10Mg (Cast Aluminum Alloy) | 2.7 | 2700 |
0.0974 |
|
AlSi12 (Cast Aluminum Alloy) |
2.65 | 2650 | 0.096 |
| AlSi14 (Cast Aluminum Alloy) | 2.7 | 2700 |
0.0974 |
|
AlSi15 (Cast Aluminum Alloy) |
2.74 | 2740 | 0.0989 |
| AlSi16 (Cast Aluminum Alloy) | 2.72 | 2720 |
0.0983 |
|
AlSi18 (Cast Aluminum Alloy) |
2.74 | 2740 | 0.0989 |
| AlSi2Cu (Cast Aluminum Alloy) | 2.75 | 2750 |
0.0995 |
|
AlSi5Cu3 (Cast Aluminum Alloy) |
2.73 | 2730 | 0.0987 |
| AlSi8Cu3 (Cast Aluminum Alloy) | 2.74 | 2740 |
0.0989 |
| AlSi9Cu3 (Cast Aluminum Alloy) | 2.71 | 2710 |
0.098 |
Methods to Measure Aluminum Density
Below are several precise methods for measuring aluminum density to ensure accuracy in industrial applications:
Hydrostatic Weighing
Hydrostatic weighing based on Archimedes’ principle is one of the most widely used density measurement methods.
It involves immersing aluminum samples in water and measuring their weight in air and immersion water.
The weight difference represents buoyancy force, which corresponds to the amount of water discharged from the sample.
Then use the following formula to calculate the density:
Direct Measurement
For simple and quick estimation, the sample mass can be determined by using a scale and the sample volume can be calculated based on size, then the density can be calculated by dividing the mass by the volume:
Pycnometer Method
For aluminum in powder form or very small samples, a pycnometer is used.
A pycnometer measures the volume of the sample by displacing a liquid (usually water or non-reactive liquid).
The sample mass is measured with a scale, and density is calculated using the standard formula:
X-Ray or Ultrasonic Testing
Advanced methods such as X-ray and ultrasonic testing can be used for accurate and non-destructive density measurement.
The X-ray method measures density by measuring the attenuation of rays passing through the material, while the ultrasonic method calculates density by analyzing the wave velocity passing through the material.
These technologies are very precise but require specialized equipment and professional knowledge.
Factors Influencing Aluminum Density
Several factors can affect the density of aluminum, even though it remains relatively stable in most conditions:
Temperature
Temperature is one of the main factors affecting aluminum density.
Aluminum will expand when heated, increase in volume, and slightly decrease in density.
On the contrary, at lower temperatures, the material shrinks, resulting in a slight increase in density.
Alloying Elements
The standard density of pure aluminum is 2.7 g/cm ³, but when mixed with elements such as silicon, magnesium, or copper, the overall density changes.
For example, silicon and copper will slightly increase density, while magnesium will decrease density.
Production Defects
For example, residual gases or impurities during the casting processes can form pores, thereby reducing the overall density of the material.
In addition, forging methods may result in uneven grain structure and residual stress, leading to localized density variations.
How Does Density Affect Aluminum Performance?
The density of aluminum is a fundamental characteristic that has a significant impact on its overall performance and versatility.
Strength and Weight
The low density of aluminum gives it an excellent strength-to-weight ratio.
Its atomic structure can form strong bonds while maintaining the lightweight of the material, thereby achieving a robust design that reduces volume without compromising durability.
Mechanical Properties
Density can affect the hardness and tensile strength of aluminum.
High-density aluminum alloys containing heavy elements such as copper come with stronger bonding strength and greater wear resistance, while low-density aluminum alloys prioritize weight reduction but sacrifice some strength.
Conductivity
The density of aluminum affects its heat transfer and conductivity.
The lightweight structure of aluminum allows for an efficient flow of electrons and heat, making it an effective material for thermal and electrical applications.
Why Density Matters in Aluminum Casting?
Density plays a crucial role in determining the quality and performance of aluminum castings, affecting their strength, accuracy, and durability.
Strength and Integrity
Density is directly related to the structural integrity of aluminum castings.
Inconsistent or low density (usually caused by porosity) can create weaknesses, thereby reducing the material’s ability to withstand pressure and load.
Achieving uniform density ensures castings are sturdy, reliable, and capable of working under harsh conditions.
Mold Filling Accuracy
The flowability of molten aluminum depends on its density, which affects its effectiveness in filling molds during the casting process.
Uneven density can lead to incomplete filling, resulting in defects, inaccurate dimensions, and surface defects.
Consistent density can achieve smooth mold filling, ensuring consistent, accurate, and defect-free casting dimensions.
Durability and Lifespan
Density also determines the durability and long-term performance of aluminum castings.
Density changes can weaken materials, reduce wear resistance, and shorten their service life.
Castings with uniform density are more durable and come with better reliability and excellent performance over time.
Conclusion
Aluminum density affects everything from strength and durability to precision and weight reduction, making it an important consideration for manufacturers and designers.
Whether working with pure aluminum or alloys, understanding and optimizing density ensures better material performance and product reliability.
At CEX Casting, we specialize in utilizing patented squeeze casting technology to deliver high-density, defect-free aluminum castings tailored to your unique needs.
Our expertise ensures superior quality and durability for every project.
Contact us today to learn how we can help you achieve density stability in aluminum castings for your next project.