Aluminum is a popular material for CNC machining. There are types and series of aluminum. The different combination among elements generates properties. Choose the right aluminum to benefit your prototype and products.
Aluminum’s atomic number is 13. It is a soft metal that accounts for 8% of Earth’s crust. As the third most abundant element after oxygen and silicon, aluminum is available easily.
Depends on surface roughness, aluminum’s color is from silver to dull gray. Aluminum is hard to be ignited and melted at 640 degrees. Aluminum lacks magnetic and is very light. Its density is 2.68.
Different aluminum alloys have different performances to meet the production needs. The basic properties can be applied to almost every aluminum alloy. According to different request, Aluminum association organize and define alloys to specific industries.
Pure aluminum is usually alloyed with elements such as magnesium, copper, silicon, etc. to form hundreds of aluminum alloys with various specific improved properties. The followings are common types and names of CNC machined aluminum alloys.
1000 series means alloy combined with 99.00% pure aluminum and other elements, which is one of the aluminum-containing series. According to the international brand naming principle, the last two Arabic numerals of series name decide the final aluminum purity. For example, 1050 aluminum must contain above 99.5% aluminum for qualification.
1000 series aluminum alloy is cheap and has low structural value because of the fewer other metal elements. The high thermal and electrical conductivity make the 1000 series become an ideal choice for the electrical industry. 1050 and 1060 are the main aluminum alloy of the 1000 series.
Copper is the main alloy element in the 2000 series, which is about 3-5%. The features of the 2000 series are high mechanical strength, high hardness( can be hardened to strength similar to steel). 2000 series is popular in the aerospace industry, mainly in the home-build aircraft sector.
2000 series’ welding and corrosion properties are poor. Sometimes the manufacturer will perform coatings and anodization to protect.
Aluminum 2024 is the most common aluminum alloy of the 2000 series. As a moderate-to-high strength alloy, it has good fatigue resistance and fracture toughness. Aluminum is highly sensitive to thermal shock and suitable for high-speed CNC machining. It can produce fine chips that can be removed easily and make complex and precise parts. Aluminum 2024 is also used in car parts, structural parts, etc.
Ultimate tensile strength: 200 – 540 MPa
Elongation at break: 14 – 20%
Modulus of elasticity: 71 – 73.1 GPa
Hardness: 70 – 120 HB
Maximum service temperature: 200 °C
Manganese is the main alloy element in the 3000 series, which is about 1-1.5%. The features of the 3000 series are better anti-rust. 3000 series aluminum is usually applied in household appliances and the chemical industry, such as cooker, kitchen equipment, chemical equipment, etc.
Silicon is the main alloy element in the 4000 series, which is about 4.5-6%. With added silicon, the 4000 aluminum alloys’ melting point is low but without brittleness, which is used for forging and welding. When anodization is applied, 4000 aluminum alloys’ color becomes dark gray. It is usually applied in the construction industry.
Magnesium is the main alloy element in the 5000 series. Magnesium aluminum alloy has high corrosion resistance, which is usually used in the offshore industry, such as shipbuilding, transportation, and bridges, etc. As the main alloy element, magnesium makes the 5000 series has features of low density, high tensile strength, and better formability. Aluminum 5052, 5083, 5754 are the common alloys of the 5000 series.
Aluminum 5052 contains magnesium and chrome. Aluminum 5052 is a non-heat-treatable alloy. It can be CNC machined easily in a hard temper than in annealed form and shows good finishes.
Aluminum 5083 contains magnesium and a small amount of chromium and manganese, which enhances the ability of corrosion resistance. It can withstand corrosion in extreme environments such as brine and industrial and chemistry. It also can withstand low temperatures without brittleness or loss of properties.
6000 series is the most common aluminum alloys series. Many of our customers choose 6000 series aluminum to be CNC machining. 6000 series contains magnesium and silicon and accordingly inherit the advantages of 4000 and 5000 series: good applicability, corrosion resistance, moderate to high strength, and machinability. 6000 series can be heat treatable to improve strength.
Aluminum 6061 is one of the common aluminum alloys and the first choice of CNC machining. You can find aluminum 6061 parts around you. Aluminum 6061 is a precipitation-hardened aluminum alloy with good mechanical welding properties. It is usually used in 5-axis CNC machining. Aluminum 6061 part made by 5-axis CNC machining is hard to deform and clear of tolerance issues. As one of the versatile aluminum alloys, aluminum 6061 material can be performed heat-treated and be easy to extrude (second in popularity only to 6063)
Ultimate tensile strength: 310 MPa
Elongation at break: 17%
Modulus of elasticity: 68.9 GPa
Hardness: 60 HRB
Aluminum 6063 has similar properties to 6061 but softer. It is easier to form than aluminum 6061. Aluminum 6063 is usually in extrusion. Complex parts with smooth surfaces like door frames, window frames are mainly made by aluminum 6063.
Aluminum 6082 has the highest strength of the 6000 series. If you prefer high strength but low budget, aluminum 6082 is an alternative to the 7000 series. Aluminum 6082 is well suitable for applications that need strength and toughness, including bridges, truss, and scaffolds. Keep in mind that aluminum is difficult to produce thin walls.
Zinc is the main alloy element in the 7000 series. The 7000 series can be heat treated. Hardness can be adjusted to 600Mpa. 7000 series alloys are well known for strength, which are specially used in the aerospace industry. As one of the super-hard aluminum alloys, it has good wear resistance and welding property but poor corrosion resistance.
Aluminum 7075 is mainly used in the high-stress application of complex and precise parts of the aerospace industry. It is well known for its extreme fatigue strength, but can’t offer the same degree of welding property. Aluminum 7075 is expensive because of the extreme material property.
Ultimate tensile strength: 434 – 580 MPa
Elongation at break: 10-15%
Modulus of elasticity: 69 – 76 GPa
Hardness: 79-86 HRB
Maximum service temperature: 100 °C
Contact us if you still have questions about aluminum CNC machining. We provide rapid prototyping aluminum parts for worldwide customers.