6061 ( Unified Numbering System (UNS) designation A96061) is a precipitation-hardened

aluminium alloy An aluminium alloy (or aluminum alloy; see spelling differences) 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 pr ...

, containing

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

and

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...

as its major

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductili ...

ing elements. Originally called "Alloy 61S", it was developed in 1935. It has good mechanical properties, exhibits good weldability, and is very commonly

extruded Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex c ...

(second in popularity only to 6063). It is one of the most common alloys of

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

for general-purpose use. 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:

Properties

The mechanical properties of 6061 depend greatly on the temper, or heat treatment, of the material.Alcoa 6061 data sheet
(pdf), accessed October 13, 2006

Young's Modulus Young's modulus E, the Young modulus, or the modulus of elasticity in tension or compression (i.e., negative tension), is a mechanical property that measures the tensile or compressive stiffness of a solid material when the force is applied ...

is regardless of temper.

6061-O

Annealed 6061 (6061-O temper) has maximum

ultimate tensile strength Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials ...

no more than ,ASTM B209ASTM B221 and maximum

yield strength In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and wi ...

no more than or . The material has elongation (stretch before ultimate failure) of 10–18%. To obtain the annealed condition, the alloy is typically heated at 415 °C for 2-3 hours.

6061-T4

T4 temper 6061 has an

of at least or and yield strength of at least . It has elongation of 10-16%.

6061-T6

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 and yield strength of at least . More typical values are and , respectively. This can exceed the yield strength of certain types of

stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's r ...

. In thicknesses of 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 is around 152 W/m K. The

fatigue limit The fatigue limit or endurance limit is the stress level below which an infinite number of loading cycles can be applied to a material without causing fatigue failure. Some metals such as ferrous alloys and titanium alloys have a distinct limit, ...

under cyclic load is for 500,000,000 completely reversed cycles using a standard RR Moore test machine and specimen. 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 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 (, ) often form as inclusions in the material. 6061 Aluminum Grain Boundaries

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. Some specially processed aluminium alloys have grain diameters which are hundreds of nanometres, but most range from a few micrometres to hundreds of micrometres.

Uses

6061 is commonly used for the following: *construction of

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

structures, such as

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...

s and

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

s, more commonly in

homebuilt aircraft Homebuilt aircraft, also known as amateur-built aircraft or kit planes, are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch", from plans, or from assembly kits.Armstrong, Kenn ...

than commercial or military aircraft.Aluminum Information at aircraftspruce.com
accessed October 13, 2006 2024 alloy is somewhat stronger, but 6061 is more easily worked and remains resistant to corrosion even when the surface is abraded. This is not the case for 2024, which is usually used with a thin

Alclad Alclad is a corrosion-resistant aluminium sheet formed from high-purity aluminium surface layers metallurgically bonded (rolled onto) to high-strength aluminium alloy core material. It has a melting point of about 500 degrees celsius, or 932 degree ...

coating for corrosion resistance. *

yacht A yacht is a sailing or power vessel used for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a , as opposed to a , such a pleasu ...

construction, including small utility

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on i ...

s.''Boatbuilding with Aluminum'', Stephen F. Pollard, 1993, *automotive parts, such as the chassis of the

Audi A8 The Audi A8 is a full-size luxury sedan manufactured and marketed by the German automaker Audi Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. As a subsidiary of its paren ...

and the Plymouth Prowler. *flashlights *aluminium cans for the packaging of food and beverages. * Scuba tanks and other high pressure gas storage cylinders (post 1995) 6061-T6 is used for: *

bicycle frame A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles: a main triangl ...

s and components *middle to high-end recurve risers *many

fly fishing Fly fishing is an angling method that uses a light-weight fishing lure, lure—called an artificial fly—to catch fish. The fly is Casting (fishing), cast using a fly rod, Fishing reel#Fly reel, reel, and specialized Fly line, weighted line. T ...

reels. *the

Pioneer plaque The Pioneer plaques are a pair of gold-anodized aluminum plaques that were placed on board the 1972 ''Pioneer 10'' and 1973 ''Pioneer 11'' spacecraft, featuring a pictorial message, in case either ''Pioneer 10'' or ''11'' is intercepted by inte ...

*the secondary chambers and baffle systems in firearm sound

suppressor A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that reduces the acoustic intensity of the muzzle report (sound of a gunshot) and muzzle rise when a gun (firearm or air gun) is discharged, b ...

s (primarily pistol suppressors for reduced weight and improved mechanical functionality), while the primary expansion chambers usually require 17-4PH or 303

titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion i ...

. *the upper and lower receivers of many non mil-spec

AR-15 rifle An AR-15-style rifle is any lightweight semi-automatic rifle based on the Colt AR-15 design. The original ArmaLite AR-15 is a scaled-down derivative of Eugene Stoner's ArmaLite AR-10 design. The then Fairchild Engine and Airplane Corporation ...

variants. *many aluminium docks and gangways, welded into place. *material used in some

ultra-high vacuum Ultra-high vacuum (UHV) is the vacuum regime characterised by pressures lower than about . UHV conditions are created by pumping the gas out of a UHV chamber. At these low pressures the mean free path of a gas molecule is greater than approximatel ...

(UHV) chambers *many parts for remote controlled

model aircraft A model aircraft is a small unmanned aircraft. Many are replicas of real aircraft. Model aircraft are divided into two basic groups: flying and non-flying. Non-flying models are also termed static, display, or shelf models. Aircraft manufactur ...

, notably

helicopter rotor A helicopter main rotor or rotor system is the combination of several rotary wings (rotor blades) with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that counteracts aero ...

components. *large

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency commu ...

antennas. *fire department rescue ladders

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

extrusion Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex c ...

s—long constant–cross-section structural shapes produced by pushing metal through a shaped

die Die, as a verb, refers to death, the cessation of life. Die may also refer to: Games * Die, singular of dice, small throwable objects used for producing random numbers Manufacturing * Die (integrated circuit), a rectangular piece of a semicondu ...

Forgings

6061 is an alloy that is suitable for hot

forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which ...

. The billet is heated through an

induction furnace An induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. Induction furnace capacities range from less than one kilogram to one hundred tons, and are used to melt iron and steel, copper, aluminum ...

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.

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 specialised centrifugal casting method. Centrifugally cast 6061 is ideal for larger rings and sleeve applications that exceed limitations of most wrought offerings.

Equivalent materials

6061 Aluminium Equivalent Table

Standards

Different forms and tempers of 6061 aluminium alloy are discussed in the following standards:6061 (3.3214, H20, A96061) Aluminum
Retrieved on 2014-11-14. * ASTM B209: Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate * ASTM B210: Standard Specification for Aluminum and Aluminum-Alloy Drawn Seamless Tubes * ASTM B211: Standard Specification for Aluminum and Aluminum-Alloy Bar, Rod, and Wire * ASTM B221: Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes * ASTM B308/308M: Standard Specification for Aluminum-Alloy 6061-T6 Standard Structural Profiles * ASTM B483: Standard Specification for Aluminum and Aluminum-Alloy Drawn Tube and Pipe for General Purpose Applications * ASTM B547: Standard Specification for Aluminum and Aluminum-Alloy Formed and Arc-Welded Round Tube * ISO 6361: Wrought Aluminium and Aluminium Alloy Sheets, Strips and Plates

References

External links

Aluminum 6061 Properties

Aluminium alloy table

{{aluminium alloys

6061 6061 ( 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. It has good mechani ...

Aerospace materials Silicon alloys Aluminium–silicon alloys