The main alloying elements of 6061 aluminum alloy are magnesium and silicon, which form Mg2Si. If it contains a certain amount of manganese and chromium, it can neutralize the bad effects of iron; sometimes a small amount of copper or zinc is added to increase the strength of the alloy without significantly reducing its corrosion resistance; there is small amount of conductive materials To offset the adverse effects of titanium and iron on conductivity; zirconium or titanium can refine the grain and control the recrystallization structure; to improve the machinability, lead and bismuth can be added. Mg2Si is solid-dissolved in aluminum, making the alloy have an artificial age hardening function. The main alloying elements in 6061 aluminum alloy are magnesium and silicon, which have medium strength, good corrosion resistance, weldability, and good oxidation effect.
Basic Information
Light non-ferrous metals refer to non-ferrous metal materials with a density of less than 4.5g/cm³, including pure metals such as aluminum, magnesium, sodium potassium calcium strontium barium, and their alloys. The common features of these metals are low density (0.53~4.5g/cm³), high chemical activity, and stable compounds with oxygen, sulfur, carbon, and halogen. Among them, aluminum and aluminum alloys are most widely used in industry. At present, its output has exceeded 1/3 of the total output of non-ferrous metal materials.
The main alloying elements in the 6000 series aluminum alloy represented by the 6061 aluminum position are magnesium and silicon, which have medium strength, good corrosion resistance, weldability and good oxidation effect. It is widely used in various industrial structural parts that require certain strength and high corrosion resistance, such as the manufacture of trucks, tower buildings, ships, trams, railway vehicles, furniture, etc.
Chemical Composition
Its main chemical composition is (mass fraction of each element):
| Copper Cu | Manganese Mn | Magnesium | Zinc Zn | Chromium Cr | Titanium | Silicon Si | Iron Fe | Aluminum Al |
| 0.15~0.4 | 0.15 | 0.8~1.2 | 0.25 | 0.04~0.35 | 0.15 | 0.4~0.8 | 0.7 | Margin |
Classification
They are four-digit aluminum alloys with magnesium and silicon as the main alloying elements and Mg2Si phase as the strengthening phase.
The first digit is a number to distinguish groups.
The last two digits are used to distinguish the material grades in the same group series and have no special meaning.
The first digit of the four-digit system and four-digit system grades indicates the category of aluminum and aluminum alloy, and its meaning is as follows:
- 1XXX series industrial pure aluminum;
- 2XXX series Al-Cu, Al-Cu-Mn alloy
- 3XXX series Al-Mn, machinable pure aluminum;
- 4XXX series Al-Si alloy;
- 5XXX series Al-Mg alloy;
- 6XXX series Al-Mg-Si alloy;
- 7XXX series Al-Zn-Mg-Cu alloy;
6061 Aluminium Alloy
Introduction
6061 is a heat-strengthened alloy with good formability, weldability, and machinability. It also has medium strength and can still maintain good operability after annealing.
The main alloying elements of 6061 alloy are magnesium and silicon, and form Mg2Si phase. If it contains a certain amount of manganese and chromium, it can neutralize the bad effects of iron; sometimes a small amount of copper or zinc is added to increase the strength of the alloy without significantly reducing its corrosion resistance; there is a small amount of conductive materials In order to offset the adverse effects of titanium and iron on conductivity; zirconium or titanium can refine the grain and control the recrystallization structure; in order to improve the machinability, lead and bismuth can be added. Mg2Si is solid-dissolved in aluminum to make the alloy have artificial age hardening function.
6061-T651 is the main alloy of 6061 alloys. It is a high-quality aluminum alloy product produced by heat treatment and pre-stretching process. Although its strength cannot be compared with 2XXX series or 7XXX series, its magnesium and silicon alloys have many characteristics and processing properties. Excellent and excellent welding characteristics and electroplating, good corrosion resistance, high toughness, and no deformation after processing, compact material without defects and easy polishing, easy color film, excellent oxidation effect, etc.、
Physical properties
Typical Physical Properties of Aluminum Alloy (Typical Physical Properties)
| Aluminum alloy grade and status | Coefficient of thermal expansion (20-100℃)μm/m·k | Melting point range (℃) | Conductivity 20℃(68℉) (%IACS) |
Resistivity 20℃(68℉) Ωm㎡/m |
Density (20℃) (g/cm³) |
| 2024-T351 | 23.2 | 500~635 | 30 | 0.058 | 2.82 |
| 5052-H112 | 23.8 | 607~650 | 35 | 0.050 | 2.72 |
| 5083-H112 | 23.4 | 570~640 | 29 | 0.059 | 2.72 |
| 6061-T651 | 23.6 | 580~650 | 43 | 0.040 | 2.73 |
| 7050-T651 | 23.5 | 490~630 | 41 | 0.0415 | 2.82 |
| 7075-T651 | 23.6 | 475~635 | 33 | 0.0515 | 2.82 |
Mechanical behavior
Typical Mechanical Properties of Aluminum Alloy (Typical Mechanical Properties)
| Aluminum alloy grade and status | Tensile strength (25°C MPa) | Yield strength (25°C MPa) | Hardness 500kg Force 10mm ball | Elongation 1.6mm (1/16in) thickness |
| 5052-H112 | 175 | 195 | 60 | 12 |
| 5083-H112 | 180 | 211 | 65 | 14 |
| 6061-T651 | 290 | 240 | 95 | 12 |
| 7050-T651 | 510 | 455 | 135 | 10 |
| 7075-T651 | 572 | 503 | 150 | 11 |
| 2024-T351 | 470 | 325 | 120 | 20 |
Corresponding grade
- National standard: 6061(LD30) GB/T 3190-2008
- ISO: AlMg1SiCu ISO 209.1-1989
- Japanese standard: A6061 JIS H4000-1999 JIS H4040-1999
- Non-standard: 65032 IS 733-2001 IS 737-2001
- EN:EN AW-6061/AlMg1SiCu EN 573-3-1994
- German standard: AlMgSi1Cu/3.3211 DIN 1725.1-1986/W-Nr
- French standard: 6061 (A-GSUC) NF A50-411 NF A50-451
- British Standard: 6061(N20/H20) BS 1470-1988
- American Standard: 6061/A96061 AA/UNS
How to calculate the weight of the aluminum plate, tube, and rod?
Aluminum plate weight (kg)=0.0000028×thickness×width×length unit (mm)
Aluminum tube weight (kg)=0.0000028×3.14×(outer diameter-inner diameter)/4×length unit (mm)
Aluminum rod weight calculation formula (kg) = 0.0000028 × 3.14 × radius × radius × length unit (mm)
State introduction
The basic state code of aluminum alloy:
- F: Free processing state
Suitable for products with special requirements for work hardening and heat treatment conditions during the molding process. The mechanical properties of the products in this state are not regulated (uncommon)
- O: annealed state
Suitable for processed products that have been fully annealed to obtain the lowest strength (occasionally)
- H: Work hardened state
It is suitable for products whose strength is increased through work hardening. After work hardening, the product can undergo (or not) additional heat treatment to reduce the strength (generally non-heat-treated reinforced materials)
- W: solid solution heat treatment state
An unstable state, which is only suitable for alloys that are naturally aged at room temperature after solution heat treatment. This state code only indicates that the product is in the natural aging stage (uncommon)
- T: heat treatment state (Different from F, O, H state)
It is suitable for products that are stable after (or without) work hardening after heat treatment. The T code must be followed by one or more Arabic numerals (usually heat treatment strengthened materials)
The state code behind our common non-heat-treated reinforced aluminum alloy is generally the letter H plus two digits. Such as 1100 H14.
Meaning of status code
Folded letter H
The letter H is usually followed by two digits:
- The first digit indicates the method of work hardening.
The first digits after H are: 1, 2, 3, 4
That is, H1* H1* means simple work hardening treatment
H2* H2* means work hardening and incomplete annealing
H3* H3* means work hardening and stabilization
H4* H4* means work hardening and painting treatment
- The second digit indicates the degree of hardening achieved by the material.
The second digit after H is: 1, 2, 3, 4, 5, 6, 7, 8, 9
H*1 Hardness between 0 and 2
H*2 1/4 hard
H*3 Hardness between 2 and 4
H*4 1/2 hard
H*5 Hardness between 4 and 6
H*6 3/4 hard
H*7 Hardness between 6 and 8
H*8 Full hard state
H*9 super hard state
(There are not many cases where H is followed by three numbers, only a few. H111 means that an appropriate amount of work hardening has been carried out after final annealing. H112 means products suitable for hot forming. H116 means 5* with magnesium content ≥ 4.0% **A product made of alloy.)
Folded letter T
The state code behind our common heat treatment strengthened aluminum alloy is generally the letter T plus one or more Arabic numerals to indicate the subdivision state of T
Add 0-10 Arabic numerals after T to indicate the subdivision state (called TX state). The number after T indicates the heat treatment procedure for the product.
- T0
After solution heat treatment, the state is cold-worked after natural aging.
It is suitable for products whose strength is improved by cold processing.
- T1
It is cooled by the high-temperature molding process and then naturally aged to a stable state.
It is suitable for products that are not subjected to cold working (straightening and leveling can be carried out, but the mechanical performance limit is not affected) after being cooled by the high-temperature forming process.
- T2
It is cooled by the high temperature forming process and naturally aged to a stable state after cold working. It is suitable for products that undergo cold processing, straightening, and leveling to increase strength after being cooled by a high-temperature forming process.
- T3
After solution heat treatment, cold working is performed, and then natural aging to a stable state. It is suitable for products that undergo cold processing, straightening, and leveling to improve strength after solution heat treatment.
- T4
After solution heat treatment, it is naturally aged to a stable state. It is suitable for products that are not undergoing cold processing after solution heat treatment (straightening and leveling can be carried out, but the mechanical performance limit is not affected).
- T5
It is cooled by the high-temperature molding process and then artificially aged. It is suitable for products that are artificially aged after being cooled by the high-temperature forming process without cold working (straightening and leveling can be carried out, but the mechanical performance limit is not affected).
- T6
The state of artificial aging after solution heat treatment. It is suitable for products that are no longer cold-worked after solution heat treatment (straightening and leveling can be carried out, but the mechanical performance limit is not affected).
- T7
The state of artificial aging after solution heat treatment. It is suitable for products whose strength has passed the highest peak point on the aging curve during artificial aging in order to obtain some important characteristics after solution heat treatment.
- T8
After solution heat treatment, it is cold worked and then artificially aged. It is suitable for products that have been cold processed, or straightened, or leveled to increase the strength of the product.
- T9
The state of artificial aging after solution heat treatment and then cold working. Suitable for products that have been cold processed to increase product strength.
- T10
After being cooled by the high-temperature forming process, it is cold-worked and then artificially aged. It is suitable for products that have been cold processed, or straightened or leveled to improve product strength.
T state and TXXX state (outside the stress relief state) Add an Arabic numeral (called TXX state) after the TX state code or add two Arabic numerals (called TXXX state), indicating that the product characteristics (such as mechanical properties, corrosion resistance, etc.) have been significantly changed. The status of the process.
- T42
It is suitable for products whose natural aging has reached a sufficiently stable state after solid solution heat treatment in O or F state, and also for products whose mechanical properties have reached T42 state after heat treatment of processed products in any state by the buyer.
- T62
It is suitable for products that have entered artificial aging after solution heat treatment in the O or F state, and also applicable to products whose mechanical properties have reached T62 state after heat treatment of processed products in any state by the buyer.
- T73
Applicable to products that are aged after solution heat treatment to achieve the specified mechanical properties and stress corrosion resistance.
- T74
Same as T73 status definition. The tensile strength of this state is greater than the T73 state but less than the T76 state.
- T76
Same as T73 status definition. The tensile strength of this state is higher than the T73 and T74 states, and the stress corrosion cracking resistance is lower than that of the T73 and T74 states, but its resistance to spalling corrosion is still better.
- T7X2
It is suitable for products whose mechanical properties and corrosion resistance have reached the T7X state after the solution heat treatment in the O or F state and the artificial aging treatment.
- T81
It is suitable for products that have undergone a 1% cold working deformation to increase their strength after solution heat treatment, and then undergo artificial aging.
- T87
It is suitable for products that undergo a solution heat treatment, which undergoes about 7% of the cold working deformation to increase the strength, and then is artificially aged.
Folded letters TX
Add “51”, or “510”, or “511” or “52” or “54” after the above-mentioned TX or TXX or TXXX status code to indicate the product status code that has undergone stress relief treatment.
- TX51
- TXX51
- TXXX51
It is suitable for thick plates, rolled or cold-finished bars and die forgings, forged rings or rolled rings that are stretched according to the specified amount after cooling from the high temperature forming process. These products are no longer stretched. Perform straightening.
The permanent deformation of thick plates is 1.5% to 3%; the permanent deformation of rolled or cold-finished bars is 1% to 3%; the permanent deformation of die forgings forged rings or rolled rings is 1% to 5% .
- TX510
- TXX510
- TXXX510
It is suitable for extruded rods, shapes, and pipes which are stretched according to the specified amount after solution heat treatment or cooling from high-temperature forming process, as well as drawn pipes. These products will not be straightened after being stretched.
The permanent deformation of extruded rods, shapes, and pipes is 1% to 3%; the permanent deformation of drawn pipes is 1.5% to 3%.
- TX511
- TXX511
- TXXX511
It is suitable for extruded rods, shapes, and pipes that are stretched according to the specified amount after solution heat treatment or cooling from the high temperature forming process, as well as drawn pipes. These products can be slightly straightened to meet standard tolerances after stretching.
The permanent deformation of extruded rods, shapes, and pipes is 1% to 3%; the permanent deformation of drawn pipes is 1.5% to 3%.
- TX52
- TXX52
- TXXX52
It is suitable for solution heat treatment or after cooling from high temperature molding process, the stress is eliminated by compression to produce 1%~5% products with permanent deformation.
- TX54
- TXX54
- TXXX54
It is suitable for die forgings in which the stress is relieved by cold shaping in the final forging die.
- T6, solution treatment (quenching), artificial aging
- T62, by annealing or F state solution treatment, artificial aging
- T61 is a special heat treatment state, requiring its strength to be lower than T6.
Spot specification in the market
- 6061 sheet stock specification: 0.3mm~350mm (thickness)
- 6061 bar stock specification: 3.0mm~500mm (diameter)
- 6061 wire spot specification: 0.1mm~20mm (wire diameter)