Aluminum A2014: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

A2014 is an Al-Cu alloy in the 2xxx series (Al-Cu(-Mg/-Mn)) principally alloyed with copper and manganese. It is part of the high-strength, heat-treatable family of aluminum alloys developed for structural components where tensile and yield strength are primary design drivers.

Strengthening in A2014 is achieved predominantly by solution heat treatment followed by quenching and artificial aging, producing fine metastable Al-Cu precipitates (primarily θ′ and θ phases) that raise yield and tensile strength. The alloy retains reasonable machinability after aging but has limited corrosion resistance and formability compared with 5xxx and 6xxx families, so protective coatings and design allowances for forming are common.

Typical industries for A2014 include aerospace fittings and structural parts, high-performance automotive components, and machined hardware for rail and defense sectors. Engineers select A2014 where a high strength-to-weight ratio and good fatigue strength are required and where the benefits of heat-treatable strength outweigh the penalties in corrosion sensitivity and formability.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (18–30%)	Excellent	Excellent (subject to design)	Fully annealed condition for forming and stress relief
H14	Low-Medium	Moderate (10–18%)	Good	Poor-to-fair	Strain-hardened, limited cold formability, not heat-treated
T5	Medium-High	Moderate (8–14%)	Fair	Poor	Cooled from elevated temperature and artificially aged
T6	High	Low-Moderate (6–12%)	Limited	Poor	Solution heat-treated and artificially aged for peak strength
T651	High	Low-Moderate (6–12%)	Limited	Poor	Solution heat-treated, stress-relieved by stretching, then artificially aged

Tempers control the balance between strength and ductility in A2014. O and H tempers are used when forming or cold working is required, while artificially aged tempers (T5/T6/T651) maximize strength at the cost of elongation and formability.

Proper selection of temper also influences downstream processing: T6/T651 gives the best static strength and fatigue resistance for structural parts, whereas O or H-series tempers are preferred for extensive bending or forming operations prior to final heat treatment.

Chemical Composition

Element	% Range	Notes
Si	0.5 max	Low silicon minimizes hard brittle intermetallics; controls casting tendencies
Fe	0.7 max	Common impurity; higher Fe reduces toughness and machinability
Mn	0.4–1.0	Controls grain structure and improves strength and fracture resistance
Mg	0.2–0.8	Contributes to age-hardening and toughness when combined with Cu
Cu	3.9–5.0	Principal strengthening element; key for precipitation hardening
Zn	0.25 max	Minor, kept low to avoid excessive sensitivity to stress-corrosion
Cr	0.10 max	Microstructure control; reduces recrystallization and improves stability
Ti	0.15 max	Grain refiner in cast/ingot processing
Others	Balance Al, residuals	Trace elements controlled to maintain consistent aging and ductility

Copper is the dominant alloying element and dictates the precipitate chemistry responsible for strength. Manganese and chromium are added in modest amounts to refine grain structure and improve elevated-temperature stability and fracture properties, while magnesium complements copper in promoting age-hardening kinetics.

Impurity limits on iron and silicon are important to maintain toughness and machinability, and to avoid excessive formation of coarse intermetallics that can act as fatigue crack initiation sites.

Mechanical Properties

A2014 exhibits high tensile and yield strengths in the peak-aged conditions, with notable trade-offs in ductility and corrosion resistance. In T6/T651 tempers typical tensile strengths approach high hundreds of MPa, while annealed conditions offer modest strength but much higher elongation for forming operations. Fatigue strength for aged A2014 is generally superior to many 5xxx alloys when properly designed and machined, but surface condition and corrosion environment strongly influence fatigue life.

Yield and tensile values are sensitive to section thickness, temper, and heat-treatment quality; thicker sections can be more difficult to solution-treat uniformly and therefore may show reduced peak-age strength and greater property scatter. Hardness correlates well with tensile properties; the transition from O to T6 can increase Brinell hardness by a factor of two to three depending on starting material and aging schedule.

Grain structure, residual porosity, and machining-induced surface damage will dominate fatigue crack initiation in high-strength components; appropriate finishing and corrosion protection are therefore integral to achieving predictable mechanical performance.

Property	O/Annealed	Key Temper (T6/T651)	Notes
Tensile Strength (UTS)	200–260 MPa	420–460 MPa	T6 values typical for thin sections; thicker sections may be lower
Yield Strength (0.2% PS)	90–140 MPa	350–410 MPa	Yield increases substantially with aging
Elongation	18–30%	6–12%	Ductility decreases with higher strength tempers
Hardness (HB)	50–75 HB	120–155 HB	Hardness tracks aging; indicative of precipitate density

Physical Properties

Property	Value	Notes
Density	2.78 g/cm³	Slightly higher than some 6xxx alloys due to Cu content
Melting Range	~500–645 °C	Solidus–liquidus range depends on alloying and local segregation
Thermal Conductivity	~110–130 W/m·K	Lower than pure Al; Cu reduces conductivity relative to 1xxx series
Electrical Conductivity	~25–40 % IACS	Reduced by alloying; depends on temper and cold work
Specific Heat	~880 J/kg·K (0.88 J/g·K)	Typical for wrought aluminum alloys at ambient temperatures
Thermal Expansion	~23.5–24.5 µm/m·K	Similar to other aluminum alloys, relevant for bonded assemblies

The presence of copper and other alloying elements reduces thermal and electrical conductivity relative to commercially pure aluminum, which is important for designers considering thermal paths or electrical applications. Density and thermal expansion are close to common aluminum structural alloys, simplifying integration into mixed-aluminum assemblies.

Melting and solidus ranges are relevant for brazing and welding process windows; localized overheating in welding can produce coarse precipitates and HAZ softening, so thermal control is important.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.5–8 mm	Thin-gauge responds well to T6; thicker sheet harder to solution treat	O, H14, T5, T6, T651	Used for machined panels and structural skins where high strength is required
Plate	8–200 mm	Bigger thicknesses show reduced hardenability; requires controlled solution treatment	O, T6, T651 (often limited thickness)	Heavy sections need specialized heat treatment and quench controls
Extrusion	Profiles up to moderate cross-sections	Extruded sections often require aging to develop strength	T5, T6 (post-extrusion)	Limited compared to 6xxx alloys; used for high-strength profiles
Tube	Ø varied	Thin-walled tubes harden well; large-diameter tubes may be annealed	O, T6	Used in structural members and hydraulic fittings
Bar/Rod	Diameters up to 150 mm	Solid bars can achieve high T6 strength if properly solution-treated	O, T6, T651	Common for machined parts such as fittings, pins, and shafts

Form type and size strongly influence achievable properties because solution treatment and quench rates determine precipitate distribution. Thin sections and small cross-sections attain near-peak strength after standard T6 aging, while large cross-sections often require modified heat-treatment cycles and tight process control to avoid under-aged cores.

Processing routes differ: sheet/plate rolling produces directional microstructures affecting anisotropy; extrusions and forgings require subsequent homogenization and aging to reach designed mechanical targets and to reduce quench sensitivity.

Equivalent Grades

Standard	Grade	Region	Notes
AA	A2014	USA	Typical wrought alloy designation in ASME/ASTM material specs
EN AW	2014	Europe	EN designations align closely but may have slightly different mechanical test requirements
JIS	A2014	Japan	Generally equivalent compositionally with possible regional tolerances
GB/T	2A14 / 2014	China	Commonly used Chinese designation; mechanical and chemical tolerances may differ slightly

Equivalent designations across standards are broadly similar compositionally, but specification tolerances, qualification testing, and allowable impurities vary by standards body. These differences affect certification for aerospace or pressure equipment and may require supplier documentation to confirm conformance to the purchaser’s standard.

When substituting between standards, check the material specification for permitted thickness ranges, temper definitions (e.g., T651 vs T6), and required mechanical property minimums to avoid field failures or qualification issues.

Corrosion Resistance

A2014 has limited general corrosion resistance compared to 5xxx and 6xxx series alloys because copper increases cathodic activity and can promote localized corrosion. In atmospheric environments it may perform acceptably when coated or anodized, but unprotected exposures, particularly in marine or chloride-containing atmospheres, accelerate pitting and intergranular attack.

Stress corrosion cracking (SCC) susceptibility is a significant concern for 2xxx-series alloys, especially under tensile stresses and elevated temperatures; peak-aged tempers (T6) and certain weld-affected zones are particularly vulnerable. Design against SCC includes using lower-strength tempers in critical zones, applying cathodic or barrier coatings, and avoiding galvanic couples to more noble metals without insulation.

Compared with 6xxx alloys, A2014 sacrifices corrosion resilience for higher strength; compared with 1xxx alloys, A2014 offers vastly greater strength but much lower conductivity and corrosion performance. Surface treatments (conversion coatings, painting, anodizing) and cladding with pure aluminum are common mitigation methods in aggressive environments.

Fabrication Properties

Weldability

Fusion welding of A2014 is challenging due to its high copper content and strong susceptibility to hot-cracking and HAZ softening. Gas tungsten arc (TIG) and gas metal arc (MIG) welding are possible with pre- and post-weld strategies, but the weld zone will generally be weaker than the T6 base metal and often requires local post-weld solution treatment and re-aging. Filler alloys with higher Si and Mg or lower Cu (e.g., 4043, 5356) are typically used to reduce cracking risk, but they create dissimilar metallurgical zones and require consideration of mechanical property gradients.

Machinability

A2014 is considered relatively good for machining among high-strength aluminum alloys due to its alloyed copper content providing chip breakage and improved strength for dimensional stability. Cutting tools of carbide or coated carbide are preferred; moderate to high cutting speeds with rigid setups and positive rake geometries minimize built-up edge. Feed rates and coolant strategies should focus on evacuating small, segmented chips and avoiding excessive tool-workpiece friction that leads to surface smearing.

Formability

Cold formability of peak-aged tempers is limited; bending and deep drawing are best performed in O or H tempers prior to final solution heat treatment and aging. Minimum bend radii for T6 sheet should be conservative (e.g., several times thickness depending on tooling) and springback must be anticipated. When complex shapes are required, near-net-shape processes or post-forming heat treatments are commonly used to achieve final mechanical properties.

Heat Treatment Behavior

A2014 is heat-treatable and follows classical precipitation-hardening sequences: solution treatment, quench, and artificial aging. Typical solution treatment temperatures are in the range of 495–530 °C with rapid quenching (water or polymer quench) to retain a supersaturated solid solution; improper quench rates produce coarse precipitates and reduced peak strength. Artificial aging schedules (e.g., T6) commonly use aging at ~160–190 °C for periods of several hours to develop the θ′ precipitate structure and attain near-maximum strength.

Temper transitions include T5 (cooled from elevated temperature and artificially aged), T6 (solution treated and artificially aged), and T651 (stress-relieved by stretching then artificially aged). Control of quench severity, aging temperature/time, and pre-aging conditions is critical for minimizing quench sensitivity, reducing distortion, and maximizing fatigue performance.

High-Temperature Performance

Like other Al-Cu alloys, A2014 experiences notable strength degradation at elevated temperatures; above approximately 120–150 °C long-term strength and creep resistance decline as precipitates coarsen and dissolve. Short-term exposure to higher temperatures during processing (e.g., welding) can over-age or dissolve strengthening precipitates, producing HAZ softening and reduced local mechanical properties. Oxidation is limited (aluminum forms a passive oxide) but scale formed at very high temperatures does not protect against mechanical property loss.

For sustained high-temperature applications, A2014 is generally not recommended; designers typically select alloys with higher temperature stability or add protective measures and deratings when transient temperature excursions are unavoidable. When used near elevated service temperatures, regular inspection for creep, stress relaxation, and SCC is recommended.

Applications

Industry	Example Component	Why A2014 Is Used
Aerospace	Fittings, clevises, forgings	High strength-to-weight and fatigue resistance in compact parts
Automotive	High-strength machined brackets and steering components	Strength for load-bearing parts with machining economy
Defense / Rail	Structural fittings and weapon components	Machinability combined with high static strength and toughness
Industrial Machinery	Gear housings and valve bodies	Ability to machine complex shapes to high strength levels

A2014 is favored for small to medium-size structural components where peak strength and machinability are critical and where corrosion exposure can be controlled. Its role in aerospace and high-performance automotive hardware remains important where weight savings and structural integrity are paramount.

Selection Insights

A2014 is chosen when high, heat-treatable strength and good machinability are prioritized over corrosion resistance and forming. Compared with commercially pure aluminum (e.g., 1100), A2014 trades off conductivity and formability for substantially higher yield and tensile strength, making it better for machined structural parts but worse for conductive or extensively formed components.

Compared with work-hardened alloys such as 3003 or 5052, A2014 provides much higher static strength and better fatigue performance but has reduced corrosion resistance and is less suitable for severe forming operations. Compared with common 6xxx heat-treatable alloys (e.g., 6061 or 6063), A2014 often offers comparable or higher strength in certain tempers and better machinability, but generally inferior corrosion resistance and lower thermal/electrical conductivity; A2014 is preferred when peak strength and fatigue resistance outweigh these disadvantages.

• Consider A2014 when design demands high static and fatigue strength with precision machining and when protective finishes or cladding can address corrosion risk. These trade-offs typically favor A2014 in aerospace fittings and high-stress machined components.
• Avoid A2014 for large thin panels requiring extensive forming, for uncoated marine structural members unless cladded, and for applications where electrical or thermal conductivity is a primary requirement.
• If weldability is essential with minimal post-weld treatment, select alternative alloys (e.g., 6xxx or 5xxx series) and reserve A2014 for predominantly machined/forged parts with controlled joining methods.

Closing Summary

A2014 remains a relevant high-strength, heat-treatable aluminum alloy for applications that demand an optimized balance of strength, machinability, and fatigue performance. Its use is most effective when designers accommodate its corrosion sensitivity and limited formability through material selection, protective treatments, and appropriate tempering and post-processing.