Aluminum alloys are widely used metal in various industries. they are lightweight and have good strength. 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 difference between each type? how they are named? in this blog, we will give you answers to these questions.
What Is Aluminum Alloy?
Aluminum alloys is mainly composed of pure aluminum, combines with other elements such as copper, silicon, magnesium and zinc to improve its properties. aluminum alloys are lightweight and have excellent corrosion resistance, good electrical and thermal conductivity.
Advantages of Aluminum Alloys
Easy to Process
Aluminum alloys are highly workable because they are soft metals that break, mold, and melt easily. This allows for easy cutting by CNC machines and smooth casting. The easy processing reduces production time and costs, while minimizing the risk of deformation, enhancing the precision and consistency of aluminum parts.
Corrosion Resistance
Aluminum alloys have high resistance to corrosion because aluminum naturedly forms a thin oxide layer on its surface, which protects against chemical wear and oxidization. Different aluminum grades differ greatly in their resistance to corrosion because the additional elements amounts, they have. The most corrosion-resistant grades are Aluminum 6061 which is widely used in the applications with corrosion environment.
Lightweight
Aluminum alloy is lightweight, its density is 2.7 g/cm³ which is one-third the density of steel. This lightweight contributes a lot in those application needs lower weight such as Automotive industry.
Electrical Conductivity
Aluminum alloys are usually found in Electrical components because aluminum have high electrical conductivity. Pure aluminum has an electrical conductivity of about 37.7 million siemens per meter at room temperature. In aluminum alloy, with other elements added, its conductivity become lower but still much better than steels and other metals but not copper.
Strength-To-Weight Ratio
Even aluminum alloy is lightweight, but aluminum alloys still can provide excellent strength and structural integrity. that is why in automotive and aerospace industries, a lot of CNC-machined aluminum parts are used. the strength-to-weight ratio differ in different grades of aluminum alloy. 7075 is stronger than 6061, so it is used a lot in aerospace and marine applications.
Recyclability
Aluminum is highly recyclable, which is perfect for CNC machining, because CNC machining is a subtractive manufacturing method which means there is a relatively large amount of waste material in the form of chips from the cutting tool. In this way CNC machining applications can use recyclable materials to reduce the cost of machined parts.
How Aluminum Alloy is Named
When we see the name of aluminum alloys. You may wonder what is number and letter means, such as 6061, 6061-T6, 7075-T651. As below, we take an example of 6061-T6 to explain to you.
The first number “6″ represents the aluminum alloy group, its detail meaning as blow:
| Group Number | Meaning |
|---|---|
| 1 | Industrial pure aluminum |
| 2 | Aluminum-copper series alloy |
| 3 | Aluminum-manganese series alloy |
| 4 | Aluminum-silicon series alloy |
| 5 | Aluminum-magnesium series alloy |
| 6 | Aluminum-magnesium-silicon series alloy |
| 7 | Aluminum-zinc-magnesium-copper series alloy |
| 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 alloys within the same group.
The rest letter’s meaning as blow:
| Temper Designation | Meaning |
|---|---|
| F | As-fabricated condition, suitable for products not requiring special hardening or heat treatment during 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.
Methods for machining Aluminum Alloys
Best Aluminum Alloys for CNC Metal Machining
| Alloy Grade | Key Properties | Application Areas |
|---|---|---|
| 2024-T4 | High strength, good fatigue resistance | Aerospace industry, aircraft fuselages, transport vehicle components, wing tension members |
| 5052 | Excellent corrosion resistance | Marine industry, manufacturing marine equipment |
| 6061-T6 | Good balance of strength and machinability | CNC machining, chassis manufacturing, bicycle frames, valves, computer components |
| 6063 | Moderate strength, high ductility | Mold forming, structural applications |
| 6082 | Higher tensile strength, good corrosion resistance | Construction, structures like bridges, towers, trusses |
| 7075-T6 | Very high strength, good fatigue strength | Aerospace and military industry, aircraft fittings, missile parts, fuses |
| MIC 6 | High precision, thermal stability | Producing stable and high-tolerance sheets, applications requiring strength-to-weight ratios, precision, elasticity |
Best Aluminum Alloys for Extrusion
| Alloy Grade | Key Properties | Common Applications |
|---|---|---|
| 6005 | Corrosion resistance, moderate strength, silicon content for enhanced extrudability | General purpose extrusions, architectural components, window frames, door frames, scaffolding, solar panel mounting systems |
| 6063 | High-quality finishes, excellent corrosion resistance, suitable for extrusion | Structural pipes, seamless tubing, heat sinks, custom/standard aluminum extrusion designs, window and door frames, fixtures, furniture |
| 6463 | High density, yield strength, composed of 98% aluminum with trace elements | Bars, tubes, rods, wire, various custom profiles, automotive components, heavy-duty structures |
Best Aluminum Alloys for Metal Casting
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 |
| Alloy Grade | Key Properties | Application Areas |
|---|---|---|
| A360 | Good formability, corrosion resistance, fatigue strength, medium static strength | Automobile oil pans, controller shells, motor shells, 5G communication boxes, LED lamp housings |
| A380 | High versatility, load-bearing capacity, resistance to high-temperature splitting | Electrical equipment chassis, engine mounts, gearboxes, furniture, generators, hand tools |
| A383 | Improved corrosion resistance, resistance to hot cracking, fluidity, and high-temperature strength | Die casting applications, equivalent to ADC12 according to JIS standard |
Best Aluminum Alloys for Sheet Metal fabrication
Due to their excellent ductility and fatigue resistance, some aluminum alloys are widely used in sheet metal fabrication. Here are some common examples:
| Alloy Grade | Key Properties | Application Areas |
|---|---|---|
| 6061 | High strength, good ductility, weldability, corrosion resistance | Aerospace, automotive, building and construction, transportation, consumer goods |
| 5052 | Excellent formability, corrosion resistance | Marine applications, heat exchangers, food and beverage industry |
| 3003 | Good formability, weldability, corrosion resistance | General fabrication, food and chemical processing, roofing and siding |
| 2024 | High strength, good fatigue resistance | Aerospace, aircraft components, structural parts |
| 7075 | Very high strength, good fatigue resistance | Aerospace, high-performance aircraft components, defense applications |
| 8011 | Excellent formability, low density | Automotive body panels, heat exchangers, beverage cans |
Comparison Table of Common Aluminum Alloys
here is comparison table as below to compare each alloy’s properties in terms of welding, machining, Corrosion Resistance and strength to help have a general view of each aluminum alloy.
| Alloy Type | Weldability | Machinability | Corrosion Resistance | Strength |
| Alloy 1100 | Easily | Good | Highly | Low |
| Alloy 2024 | Challenging | Fair | Limited | High |
| Alloy 3003 | Easily | Good | Good | Medium |
| Alloy 5052 | Easily | Fair | Excellent | Medium |
| Alloy 6061 | Excellent | Good | Excellent | Medium |
| Alloy 6063 | Easily | Fair | Good | Medium |
| Alloy 7075 | Challenging | Fair | Fair | High |
Physical Properties of Aluminum Alloys
Here is a table as below to show all the physical properties of aluminum alloys.
| 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 |
FAQ
How to Choose an Aluminum Grade?
Before you chose the aluminum, you will need to consider your machined parts requirement and the machining process you will use. some of general consideration 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.
Weldability
If you will use aluminum alloy for CNC machining, it is better to choose the one easy to be machined. Aluminum 6061 has a good Machinability for machining.
Which is more expensive to machine, aluminum alloy or steel?
Under normal circumstances, the material cost of aluminum alloy is higher compared to steel.
However, when it comes to machining, more factors need to be considered. For instance, factors such as Machining Difficulty, Machining Time, and Material Availability should be taken into account.
Therefore, the actual needs must be evaluated to determine which metal, aluminum alloy or steel, offers a more cost-effective advantage in manufacturing.
Which material should be used for aluminum alloy and titanium?
Titanium has a lower density, higher strength, superior corrosion resistance, biocompatibility, heat resistance, and a lower coefficient of thermal expansion than aluminum alloys.
However, it’s more expensive in terms of material and processing costs. The choice between aluminum alloy and titanium should be based on your application requirements, performance needs, budget, and manufacturing capabilities.
Conclusion
Using a proper Aluminum alloy for your products is the key for quality. you may need to choose a professional supplier who are capable of managing different types of aluminum alloys. KUSLA have rich experiences of aluminum machining services can help you for your projects. contact us today to get an instant quotation.
Copyright Notice: Portions of this article “Industry Standards | The Aluminum Association” are included in this post with the copyright belonging to the original author.
