Aluminum alloys are widely used metals in various industries. There are many different types of aluminum alloys with different names in the market. how do you know which one is suitable for your project? where are the differences between each type? how they are named? in this blog, we will give you answers to these questions.
What Is Aluminum Alloy?
Aluminum alloys are mainly composed of pure aluminum, combined with other elements such as copper, silicon, magnesium, and zinc to improve its properties. aluminum alloys are lightweight and have excellent corrosion resistance and good electrical and thermal conductivity.
How Aluminum Alloy is Named
When we see the name of aluminum alloys. You may wonder what number and letters means, such as 6061, 6061-T6, and 7075-T651. As below, we take an example of 6061-T6 to explain to you.
The first number “6″ represents the aluminum alloy group, and its detailed meaning as below:
| Group Number | Meaning | Characteristic |
|---|---|---|
| 1 | Industrial pure aluminum | Easy to form and highly machinable |
| 2 | Aluminum-copper series alloy | excellent machinability, less corrosion resistance |
| 3 | Aluminum-manganese series alloy | moderate strength and excellent workability |
| 4 | Aluminum-silicon series alloy | suitable for casting applications |
| 5 | Aluminum-magnesium series alloy | good strength and corrosion resistance |
| 6 | Aluminum-magnesium-silicon series alloy | moderate strength and excellent workability |
| 7 | Aluminum-zinc-magnesium-copper series alloy | high strength, but low machinability |
| 8 | Other alloys | |
| 9 | Reserved or for future use |
the second number “0” Indicates the control of alloying elements or impurities’ maximum content as below:
| Second Digit | Meaning |
|---|---|
| 0 | Original alloy, no special control over impurity max content |
| 1-9 | Modified alloy, special control over one or more individual impurities or alloying element max-content |
the number “61″ represents a kind of alloy within the same group.
The rest letters’ meanings are as below:
| Temper Designation | Meaning |
|---|---|
| F | As-fabricated condition, suitable for products not requiring special hardening or heat treatment during the forming process |
| O | Annealed condition, results in a material that is easier to machine, tougher, and more ductile; can be followed by a single-digit numeral except 0 |
| H | Strain-hardened condition, for non-heat-treatable alloys where strength is increased by strain hardening |
| W | Solution heat-treated condition, unstable and only applicable to alloys naturally aged at room temperature after solution heat treatment |
| T | Heat-treated condition to a stable state, for heat-treatable alloys where the product reaches a stable state after heat treatment |
For example, “6061-T6” indicates an alloy from the aluminum-magnesium-silicon series that has undergone solution heat treatment and artificial aging to achieve a stable temper.
Types Of Aluminum alloy
Wrought Aluminum Alloy
Wrought aluminum alloys have a big portion of all kinds of aluminum alloys. they are divided into heat-treatable and non-heat-treatable alloys. they contain Copper, magnesium, and zinc which provide their initial strength. Corresponding to series 2xxx, 6xxx, and 7xxx, Heat-treatable wrought aluminum alloys can be strengthened further through heat treatment. Non-heat treatable Aluminum Alloy corresponds to the 1xx, 3xx, and 5xx series of wrought alloys, it can be strengthened further through strain hardening or cold working.
Cast Aluminum Alloys
Aluminum alloys for die casting have several types like aluminum-silicon, aluminum-copper, aluminum-magnesium, aluminum-zinc, and more. The common grades for die-casting aluminum alloys are defined by the standards of Japan’s JIS and ANSI. The table below shows common die-casting grade series under various standards.
| Casting aluminum alloy type | ANSI | SAE J452 | JIS | DIN | GB |
| AI-Si-Mg | 360 | 309 | n/a | n/a | YL104 |
| A360 | 309 | ADC3 | AlSi10Mg (Fe) | YL101 | |
| AI-Si-Cu | A380 | 306 | ADC10 | AlSi8Cu3Fe | YL112 |
| A383 | 383 | ADC12 | AlSi12(Cu) | YL113 | |
| A384 | 303 | ADC14 | AlSi12 | YL116 | |
| AI-Si | A413 | 305 | ADC6 | AlSi10Mg | YL102 |
| C443 | 304 | ADC7 | n/a | n/a | |
| AI-Mg | 518 | n/a | ADC5 | AIMg9 | YL302 |
Advantages of Aluminum Alloys
Easy to machine
Aluminum alloys are relatively soft compared with other metals such as Steel. this characteristic makes it easy to be cut by the CNC bits and molded, and then result in aluminum parts with high precision and consistency.
Lightweight
Aluminum alloy’s density is 2.7 g/cm³ which is one-third the density of steel. This makes Aluminum alloy lightweight and widely used a lot in applications that need lower weight such as the Automotive industry.
Corrosion Resistance
Aluminum can form a thin protective oxide layer on its surface naturally, This protective aluminium oxide layer helps protect the surface of the aluminum part from corrosion.
Electrical and Thermal Conductivity
Aluminum alloy is an excellent conductor of heat and electricity. its conductivity is much better than steel and other metals but not copper which makes it widely used in lots of Electrical components. It is also used as a heatsink in a variety of applications to conduct heat.
Strength-To-Weight Ratio
Even though aluminum alloy is lightweight, aluminum alloys still provide excellent strength and structural integrity. this makes them widely used in various applications where strength and weight need to be balanced.
Recyclability
aluminum is 100% recyclable and it can retain all of its original properties after recycling, this makes aluminum a much more cost-effective source material for production.
Common Aluminum Alloys for Machining
Aluminum alloys can be used for different machining processes such as CNC machining, sheet metal fabrication, extrusion, and die casting. Based on the Characteristics of each machining process, different types of aluminum alloys are used. Here we list the common aluminum alloys for different machining processes.
For CNC machining
- 2024-T4: primarily used in the aerospace industry
- 5052: often used in the marine industry
- 6061-T6: most widely used in various industries.
- 6063: moderate strength and high ductility
- 6082: used in the construction industry
- 7075-T6: it is used in the aerospace and military industry
Read more in our blog about CNC Aluminum, you will get more details from it.
For Aluminum Extrusion
- 6005: contains silicon content which enhances extrudability.
- 6063: widely used in custom structural pipes, tubing, and heat sinks.
- 6463: used for various custom profiles.
For Aluminum die-casting
- A360: Its applications include the manufacture of automobile oil pans, automobile controller shells, motor shells, 5G communication boxes, LED lamp housings, and more.
- A380: It is used for products like electrical equipment chassis, engine mounts, gearboxes, furniture, generators, and hand tools.
- A383: the most common die-casting aluminum alloy used in the market. it is equivalent to ADC12 according to JIS standards.
For Sheet metal fabrication
- 6061: most widely used in various industries.
- 5052: often used in the marine industry
Physical Properties of Common Aluminum Alloys
Here we summarize a table below to show all the physical properties of aluminum alloys, so then you can understand the performance of each aluminum alloy.
| Alloy | Yield Strength (MPa) | Elongation at Break (%) | Hardness (Brinell) | Density (g/cm³) | Maximum Temp (°C) |
|---|---|---|---|---|---|
| Aluminum 1110 | 25-30 | 35-40 | 23 | 2.71 | 250 |
| Aluminum 2011 | 290 | 10 | 95 | 2.82 | 120 |
| Aluminum 2024 | 325-470 | 10-25 | 120-130 | 2.78 | 150 |
| Aluminum 3003 | 110-130 | 20-25 | 40 | 2.73 | 260 |
| Aluminum 5052 | 170-215 | 12-20 | 60 | 2.68 | 200 |
| Aluminum 6061 | 240-310 | 12-25 | 95 | 2.70 | 250-300 |
| Aluminum 6063 | 110-180 | 12-20 | 60 | 2.69 | 200 |
| Aluminum 7050 | 460-510 | 10-14 | 150 | 2.81 | 150 |
| Aluminum MIC-6 | 110 | 15 | 70 | 2.70 | 200 |
| A360.0 | 186 | 3.5 | 80 | 2.63 | 300 |
| A380.0 | 152 | 3.5 | 80 | 2.71 | 300 |
| A383.0 (ADC12) | 175 | 3.5 | 80 | 2.74 | 300 |
| A413.0 | 124 | 5 | 70 | 2.66 | 300 |
How to Choose an Aluminum Grade?
Before you choose aluminum, you will need to consider your machined parts requirement and the machining process you will use. some of the general considerations are as below:
Strength Requirements
from the above introduction of each aluminum alloy, you will find their strength properties. Aluminum 7075 has the best strength among those.
Corrosion Resistance
Consider the environment in which your aluminum components will be exposed. Some aluminum alloys offer exceptional corrosion resistance like 5052 or 6061, known for their corrosion resistance.
Weldability
If your project requires welding, ensure that the chosen aluminum grade is weldable. aluminum 6061 is more weldable than 7075.
Machinability
If you will use aluminum alloy for CNC machining, it is better to choose one easy to be machined. Aluminum 6061 has good Machinability for machining.
What is the best aluminum alloy for CNC machining?
Generally speaking, According to the market data, 6061-T6 is the most popular aluminum alloy for CNC machining. It’s versatile and easy to machine, 6061-T6 is a general-purpose material applicable for many applications.
However, Using a proper Aluminum alloy for your products is the key to quality. you may need to choose a professional supplier who is capable of managing different types of aluminum alloys. KUSLA has rich experiences in aluminum machining services that can help you with your projects. contact us today to get an instant quotation.
You may also want to know about the Methods for creating metal prototypes, please click the link to view our blog.
FAQ
What is the most common aluminum alloy sheet?
Generally, 3003 aluminum is the well-known and most widely used of the common alloys in the market.
Which aluminum alloy has better machinability between 6061 and 7075?
Generally speaking, in most applications, 6061 aluminum alloy is better than 7075 aluminum when considering their fabrication process. This is because 6061 has lower hardness and tensile strength, and more easier to machine than 7075. find out more in our blog: 6061 aluminum vs 7075 aluminum.
