6061 aluminium alloy

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A6061
Material typeAlloy
Alloy properties
UNS identifier A96061
Physical properties
Density (ρ)2.70 g/cm3 [1]
Mechanical properties
Young's modulus (E)68 GPa (9,900 ksi)
Tensile strength (σt)124–290 MPa (18.0–42.1 ksi)
Elongation (ε)at break 12–25%
Poisson's ratio (ν)0.33
Thermal properties
Melting temperature (Tm)585 °C (1,085 °F)
Thermal conductivity (k)151–202 W/(m·K)
Linear thermal expansion coefficient (α)2.32×10−5 K−1
Specific heat capacity (c)897 J/(kg·K)
Electrical properties
Volume resistivity (ρ)32.5–39.2 nOhm·m

6061 aluminium alloy (Unified Numbering System (UNS) designation A96061) is a precipitation-hardened aluminium alloy, containing magnesium and silicon as its major alloying elements. Originally called "Alloy 61S", it was developed in 1935. [2] It has good mechanical properties, exhibits good weldability, and is very commonly extruded (second in popularity only to 6063). [3] It is one of the most common alloys of aluminium for general-purpose use.

Contents

It is commonly available in pre-tempered grades such as 6061-O (annealed), tempered grades such as 6061-T6 (solutionized and artificially aged) and 6061-T651 (solutionized, stress-relieved stretched and artificially aged).

Chemical composition

6061 Aluminium alloy composition by mass: [4]

6061 Aluminium alloy
Constituent
element		Minimum
(% by weight)		Maximum
(% by weight)
Al 95.85%98.56%
Mg 0.80%1.20%
Si 0.40%0.80%
Fe 00.70%
Cu 0.15%0.40%
Cr 0.04%0.35%
Zn 00.25%
Ti 00.15%
Mn 00.15%
(others)00.15% total
(0.05% each)

Properties

The mechanical properties of 6061 depend greatly on the temper, or heat treatment, of the material. [5] Young's Modulus is 69 GPa (10,000 ksi) regardless of temper. [6]

6061-O

Annealed 6061 (6061-O temper) has maximum ultimate tensile strength no more than 150 MPa (22 ksi), [7] [8] and maximum yield strength no more than 83 MPa (12 ksi) [7] or 110 MPa (16 ksi). [8] The material has elongation (stretch before ultimate failure) of 10–18%. To obtain the annealed condition, the alloy is typically heat soaked at 415 °C for 2-3 hours. [9]

6061-T4

T4 temper 6061 has an ultimate tensile strength of at least 180 MPa (26 ksi) [8] or 210 MPa (30 ksi) [7] and yield strength of at least 110 MPa (16 ksi). It has elongation of 10-16%.

6061-T6

6061-T6 aluminium standard heat treating process 6061 Aluminum Heat Treating Process.svg
6061-T6 aluminium standard heat treating process

T6 temper 6061 has been treated to provide the maximum precipitation hardening (and therefore maximum yield strength) for a 6061 aluminium alloy. It has an ultimate tensile strength of at least 290 MPa (42 ksi) and yield strength of at least 240 MPa (35 ksi). More typical values are 310 MPa (45 ksi) and 270 MPa (39 ksi), respectively. [10] This can exceed the yield strength of certain types of stainless steel. [11] In thicknesses of 6.35 mm (0.250 in) or less, it has elongation of 8% or more; in thicker sections, it has elongation of 10%. T651 temper has similar mechanical properties. The typical value for thermal conductivity for 6061-T6 at 25 °C (77 °F) is around 152 W/m K. The fatigue limit under cyclic load is 97 MPa (14 ksi) for 500,000,000 completely reversed cycles using a standard RR Moore test machine and specimen. [12] Note that aluminium does not exhibit a well defined "knee" on its S-N curve, so there is some debate as to how many cycles equates to "infinite life". Also note the actual value of fatigue limit for an application can be dramatically affected by the conventional de-rating factors of loading, gradient, and surface finish.

Microstructure

Different aluminium heat treatments control the size and dispersion of Mg
2Si precipitates in the material. Grain boundary sizes also change, but do not have as important of an impact on strength as the precipitates. Grain sizes can change orders of magnitude based upon stress and can have grains as small as a few hundred nanometres, but are typically a few micrometres to hundreds of micrometres in diameter. Iron, manganese, and chromium secondary phases (Fe
2Si
2Al
9, (Fe, Mn, Cr)
3SiAl
12) often form as inclusions in the material. [13]

Grain boundaries in extruded plate 6061 aluminium alloy 6061 Aluminum Grain Boundaries.png
Grain boundaries in extruded plate 6061 aluminium alloy

Grain sizes in aluminium alloys are heavily dependent upon the processing techniques and heat treatment. Different cross-sections of material which has been stressed can cause order of magnitude differences in grain size. [14] Some specially processed aluminium alloys have grain diameters which are hundreds of nanometres, [15] but most range from a few micrometres to hundreds of micrometres. [16]

Uses

6061 is commonly used for the following:

6061-T6 is used for:

Welding

6061 is highly weldable, for example using tungsten inert gas welding (TIG) or metal inert gas welding (MIG). Typically, after welding, the properties near the weld are those of 6061-T4, a loss of strength of around 40%. The material can be re-heat-treated to restore near -T6 temper for the whole piece. After welding, the material can naturally age and restore some of its strength as well. Most strength is recovered in the first few days to a few weeks. Nevertheless, the Aluminum Design Manual (Aluminum Association) recommends the design strength of the material adjacent to the weld to be taken as 165 MPa/24000 PSI without proper heat treatment after the welding. Typical filler material is 4043 or 5356.

Extrusions

6061 is an alloy used in the production of extrusions—long constant–cross-section structural shapes produced by pushing metal through a shaped die.

Cold and Hot Stamping

6061 sheet in the T4 condition can be formed with limited ductility in the cold state. For deep draw and complex shapes, and for the avoidance of spring-back, an aluminium hot stamping process (Hot Form Quench) can be used, which forms a blank at a elevated temperature (~ 550 C) in a cooled die, leaving a part in W-temper condition before artificial aging to the T6 full strength state.

Forgings

6061 is an alloy that is suitable for hot forging. The billet is heated through an induction furnace and forged using a closed die process. This particular alloy is suitable for open die forgings. Automotive parts, ATV parts, and industrial parts are just some of the uses as a forging. Aluminium 6061 can be forged into flat or round bars, rings, blocks, discs and blanks, hollows, and spindles. 6061 can be forged into special and custom shapes. [25]

Castings

6061 is not an alloy that is traditionally cast due to its low silicon content affecting the fluidity in casting. It can be suitably cast using a specialized centrifugal casting method. Centrifugally cast 6061 is ideal for larger rings and sleeve applications that exceed the limitations of most wrought offerings. [26]

Equivalent materials

6061 Aluminium Equivalent Table [27]

USEuropean UnionISOJapanChina
StandardGrade (UNS)SAE AMS StandardGradeStandardNumerical (Chemical Symbols)StandardGradeStandardGradeStandardGrade
AA;

ASTM B209;

ASTM B211;

ASTM B221;

ASTM B210;

ASTM B308/B308M;

ASTM B241/B241M

6061 (UNS A96061)SAE AMS 4025;

SAE AMS 4026;

SAE AMS 4027;

SAE AMS 4117

6061EN 573-3EN AW-6061

(EN AW-AlMg1SiCu)

ISO 209AW-6061JIS H4000;

JIS H4040

6061GB/T 3880.2

GB/T 3190

6061

Standards

Different forms and tempers of 6061 aluminium alloy are discussed in the following standards: [28]

Related Research Articles

<span class="mw-page-title-main">Aluminium alloy</span> Alloy in which aluminium is the predominant metal

An aluminium alloy (UK/IUPAC) or aluminum alloy is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for wrought products, for example rolled plate, foils and extrusions. Cast aluminium alloys yield cost-effective products due to the low melting point, although they generally have lower tensile strengths than wrought alloys. The most important cast aluminium alloy system is Al–Si, where the high levels of silicon (4–13%) contribute to give good casting characteristics. Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required.

7075 aluminium alloy (AA7075) is an aluminium alloy with zinc as the primary alloying element. It has excellent mechanical properties and exhibits good ductility, high strength, toughness, and good resistance to fatigue. It is more susceptible to embrittlement than many other aluminium alloys because of microsegregation, but has significantly better corrosion resistance than the alloys from the 2000 series. It is one of the most commonly used aluminium alloys for highly stressed structural applications and has been extensively used in aircraft structural parts.

2024 aluminium alloy is an aluminium alloy, with copper as the primary alloying element. It is used in applications requiring high strength-to-weight ratio, as well as good fatigue resistance. It is weldable only through friction welding, and has average machinability. Due to poor corrosion resistance, it is often clad with aluminium or Al-1Zn for protection, although this may reduce the fatigue strength. In older systems of terminology, 2XXX series alloys were known as duralumin, and this alloy was named 24ST.

5086 aluminium alloy is an aluminium–magnesium alloy, primarily alloyed with magnesium. It is not strengthened by heat treatment, instead becoming stronger due to strain hardening, or cold mechanical working of the material.

AA 6063 is an aluminium alloy, with magnesium and silicon as the alloying elements. The standard controlling its composition is maintained by The Aluminum Association. It has generally good mechanical properties and is heat treatable and weldable. It is similar to the British aluminium alloy HE9.

ASTM A992 steel is a structural steel alloy often used in the US for steel wide-flange and I beams. Like other carbon steels, the density of ASTM A992 steel is approximately 7850 kg/m3. ASTM A992 steel has the following minimum mechanical properties, according to ASTM specification A992/A992M. Tensile yield strength, 345 MPa (50 ksi); tensile ultimate strength, 450 MPa (65 ksi); strain to rupture in a 200-mm-long test specimen, 18%; strain to rupture in a 50-mm-long test specimen, 21%.

5059 aluminium alloy is an aluminium–magnesium alloy, primarily alloyed with magnesium. It is not strengthened by heat treatment, instead becoming stronger due to strain hardening, or cold mechanical working of the material.

2014 aluminium alloy (aluminum) is an aluminium-based alloy often used in the aerospace industry.

7068 aluminium alloy is one of the strongest commercially available aluminium alloys, with a tensile strength comparable to that of some steels. This material, also known as an aircraft alloy, is heat treatable.

5154 aluminium alloy is an alloy in the wrought aluminium-magnesium family. As an aluminium-magnesium alloy, it combines moderate-to-high strength with excellent weldability. 5154 aluminium is commonly used in welded structures such as pressure vessels and ships. As a wrought alloy, it can be formed by rolling, extrusion, and forging, but not casting. It can be cold worked to produce tempers with a higher strength but a lower ductility. It is generally not clad.

5454 aluminium–magnesium alloy is an alloy in the wrought aluminium-magnesium family. It is closely related to 5154 aluminium alloy. As an aluminium-magnesium alloy, it combines moderate-to-high strength with excellent weldability. Like 5154, 5454 aluminium is commonly used in welded structures such as pressure vessels and ships. As a wrought alloy, it can be formed by rolling, extrusion, and forging, but not casting. It can be cold worked to produce tempers with a higher strength but a lower ductility. It is generally not clad.

5456 aluminium–magnesium alloy is an alloy in the wrought aluminium-magnesium family. While it is closely related to 5356 aluminium alloy, it is used in structural applications, like most other aluminium-magnesium alloys, and not as filler for welding. As a wrought alloy, it can be formed by rolling, extrusion, and forging, but not casting. It can be cold worked to produce tempers with a higher strength but a lower ductility. It is susceptible to exfoliation corrosion when held at temperatures above 65 °C (150 °F) for extended periods of time.

5754 aluminium–magnesium alloy is an alloy in the wrought aluminium -magnesium family. It is closely related to the alloys 5154 and 5454. Of the three 5x54 alloys, 5754 is the least alloyed, but only by a small amount. It is used in similar applications. As a wrought alloy, it can be formed by rolling, extrusion, and forging, but not casting. It can be cold worked to produce tempers with a higher strength but a lower ductility.

6005 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is closely related, but not identical, to 6005A aluminium alloy. The main difference between the two alloys is that 6005 has a higher minimum composition percentage of aluminium than 6005A. The most common forming method is extrusion. It can also be forged or rolled, but as a wrought alloy it is not used in casting. It is commonly heat treated to produce tempers with a higher strength at the expense of ductility.

6005A aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is closely related, but not identical, to 6005 aluminium alloy. Between those two alloys, 6005A is more heavily alloyed, but the difference does not make a marked impact on material properties. It can be formed by extrusion, forging or rolling, but as a wrought alloy it is not used in casting. It cannot be work hardened, but is commonly heat treated to produce tempers with a higher strength at the expense of ductility.

6060 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is much more closely related to the alloy 6063 than to 6061. The main difference between 6060 and 6063 is that 6063 has a slightly higher magnesium content. It can be formed by extrusion, forging or rolling, but as a wrought alloy it is not used in casting. It cannot be work hardened, but is commonly heat treated to produce tempers with a higher strength but lower ductility.

6105 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is one of the least common of the alloys in this series. While most wrought aluminium alloys are covered by multiple standards, 6105 is only dealt with in ASTM B221: Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes. It is formed by extrusion, and supplied in heat treated form. It can alternately referred to by the UNS designation A96105.

6162 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is related to 6262 aluminium alloy in that Aluminum Association designations that only differ in the second digit are variations on the same alloy. It is similar to 6105 aluminium alloy, both in alloy composition and the fact that it is only really used in extrusions. However, as a wrought alloy, it can also be formed by rolling, forging, and similar processes, should the need arise. It is supplied in heat treated form. It can be referred to by the UNS designation A96162, and is covered by the standard ASTM B221: Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes.

6262 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family. It is related to 6162 aluminium alloy, but sees much more widespread use. It is notably distinct from 6162, and most other aluminium alloys, in that it contains lead in its alloy composition. It is typically formed by extrusion, forging, or rolling, but as a wrought alloy it is not used in casting. It can also be clad, but that is not common practice with this alloy. It cannot be work hardened, but is commonly heat treated to produce tempers with a higher strength but lower ductility.

The 6463 aluminium alloy is an aluminium alloy in the wrought aluminium-magnesium-silicon family. It is related to 6063 aluminium alloy, but unlike 6063 it is generally not formed using any processes other than extrusion. It is commonly heat treated to produce tempers with a higher strength but lower ductility. Like 6063, it is often used in architectural applications.

References

  1. ↑ ASM Handbook Volume 2: Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (10 ed.). Materials Park, Ohio. 1990. ISBN   978-0-87170-377-4. OCLC   21034891.{{cite book}}: CS1 maint: location missing publisher (link)
  2. ↑ Robert E. Sanders Jr. (2001). "Technology Innovation in Aluminum Products" . JOM. 53 (2): 21–25. Bibcode:2001JOM....53b..21S. doi:10.1007/s11837-001-0115-7. S2CID   111170376.
  3. ↑ "Aluminum Alloys". Materials Management Inc. 23 December 2015. Archived from the original on 31 July 2016. Retrieved 2016-07-25.
  4. ↑ Specification for Aluminum and Aluminum-Alloy Sheet and Plate (metric) (Report). B07 Committee. doi:10.1520/b0209m-14.
  5. ↑ Alcoa 6061 data sheet Archived 2006-10-20 at the Wayback Machine (pdf), accessed October 13, 2006
  6. ↑ Aluminum Standards and Data 2006 Metric SI, by the Aluminum Association Inc.
  7. 1 2 3 ASTM B209
  8. 1 2 3 ASTM B221
  9. ↑ ASM Handbook Committee (1991). "Heat Treating of Aluminum Alloys". Volume 4: Heat Treating (PDF). ASM. p. 871. doi:10.1361/asmhba0001205 (inactive 2024-09-12). hdl:11115/192.{{cite book}}: CS1 maint: DOI inactive as of September 2024 (link)
  10. ↑ Material Properties Data: 6061-T6 Aluminum
  11. ↑ "ASM Material Data Sheet". Archived from the original on 2018-10-01. Retrieved 2020-12-23.
  12. ↑ "ASM Material Data Sheet". Archived from the original on 2018-10-22. Retrieved 2010-03-21.
  13. ↑ Hatch, John (1984). "Microstructure of Alloys". Aluminum: Properties and Physical Metallurgy. ASM International. pp. 54–104. ISBN   9780871701763.
  14. ↑ Nakai, Manabu; Itoh, Goroh (2014). "The Effect of Microstructure on Mechanical Properties of Forged 6061 Aluminum Alloy". Materials Transactions. 55 (1): 114–119. doi: 10.2320/matertrans.ma201324 . ISSN   1345-9678.
  15. ↑ Lee, S. H; Saito, Y; Sakai, T; Utsunomiya, H (2002-02-28). "Microstructures and mechanical properties of 6061 aluminum alloy processed by accumulative roll-bonding". Materials Science and Engineering: A. 325 (1): 228–235. doi:10.1016/S0921-5093(01)01416-2. ISSN   0921-5093.
  16. ↑ Easton, M.A.; StJohn, D.H. (2008). "Improved prediction of the grain size of aluminum alloys that includes the effect of cooling rate". Materials Science and Engineering: A. 486 (1–2): 8–13. doi:10.1016/j.msea.2007.11.009.
  17. ↑ Aluminum Information at aircraftspruce.com, accessed October 13, 2006
  18. ↑ 6061 vs 2024 Archived 2013-01-25 at archive.today . Homebuiltairplanes.com. Retrieved on 2012-04-04.
  19. ↑ Boatbuilding with Aluminum, Stephen F. Pollard, 1993, ISBN   0-07-050426-1
  20. ↑ Sorokanich, Bob (16 December 2015). "The Plymouth Prowler Was Secretly Chrysler's Most Important Engineering Experiment". Road & Track . Archived from the original on 28 January 2022. Retrieved 2 November 2022.
  21. ↑ Koch, Susanne (9 June 2021). "What aluminium alloys are best for bicycle frames?". Shapes – The Aluminium Design Knowledge Hub. Archived from the original on 26 October 2021. Retrieved 27 September 2022.
  22. ↑ EVOLUTION 9mm, 1/2-28 TPI Archived 2011-08-01 at the Wayback Machine . Advanced Armament. Retrieved on 2012-04-04.
  23. ↑ Amphibian S .22LR : Suppressor : AWC Systems Technology Archived 2011-10-01 at the Wayback Machine . Awcsystech.com. Retrieved on 2012-04-04.
  24. ↑ Bothell, Jed (30 September 2015). "Next Generation Vacuum Systems: Aluminum". Atlas Technologies. Archived from the original on 17 January 2022. Retrieved 27 September 2022.
  25. ↑ "6061 Aluminum Alloy Forging | Anderson Shumaker". www.andersonshumaker.com. Archived from the original on 2016-01-17. Retrieved 2015-10-08.
  26. ↑ "Aluminum Alloys | Johnson Centrifugal". johnsoncentrifugal.com. 27 August 2019. Retrieved 2019-10-14.
  27. ↑ Cole, Andrew (2020-05-24). "AL 6061-T6 Aluminium Alloy Properties, Tensile & Yield Strength, Thermal Conductivity, Modulus of Elasticity, Equivalent Material". The World Material. Retrieved 2020-08-03.
  28. ↑ 6061 (3.3214, H20, A96061) Aluminum. Retrieved on 2014-11-14.

Further reading

Aluminium alloy table

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