What Is 3003 Aluminium Alloy?
3003 is an aluminium-manganese alloy, designated 3.0517 under EN and A93003 under the unified numbering system. Manganese is the principal alloying element, present in the range of 1.0% to 1.5%, which gives the alloy noticeably higher strength than the 1xxx series while retaining excellent formability and corrosion resistance. Because it is not heat treatable, the strength of 3003 is developed by cold working, and the material is therefore supplied in a range of strain-hardened tempers as well as the annealed O condition.
The chemical composition is defined by standards such as EN 573-3 and ASTM B221. In addition to manganese, the composition allows up to 0.7% iron, up to 0.6% silicon, 0.05% to 0.20% copper and up to 0.10% zinc, with the balance being aluminium. The copper addition gives 3003 slightly higher strength than a simple binary aluminium-manganese alloy.
Physical and Mechanical Properties
Typical physical properties of 3003 sheet are a density of about 2.73 g/cm3, a melting range around 640 to 655 degrees Celsius, a coefficient of thermal expansion of about 23.1 x 10-6 per kelvin, a modulus of elasticity of about 69.5 GPa and a thermal conductivity of approximately 190 W/(m·K). These values place 3003 between pure aluminium and the higher-strength alloys in both weight and conductivity.
For sheet in the O temper, tensile strength is typically in the range of 95 to 135 MPa with a proof stress of about 35 MPa minimum, per EN 485-2. Cold-worked tempers such as H14 increase the strength substantially, with typical tensile values around 140 to 180 MPa depending on the degree of working, at the expense of reduced elongation. Selection of temper is therefore driven by the balance between strength and formability required by the application.
Temper Selection
The O temper is fully annealed and offers maximum ductility for deep drawing, spinning and severe forming. It is the normal temper for applications where the sheet will be formed into shape and may be work-hardened during the forming process itself.
Strain-hardened tempers H14, H16, H18 and H24 are used where the sheet must keep its shape after forming and where higher strength is needed. The H24 temper is a strain-hardened and partially annealed condition that combines good strength with improved ductility compared with the equivalent H2x temper. The H112 temper is available for thicker plate delivered from the hot-working process.
Weldability and Fabrication
3003 has very good weldability by gas, arc and resistance methods, and it is one of the easiest aluminium alloys to braze and solder. Cold formability is rated very good, while machinability is acceptable; for extensive machining, free-cutting alloys may be preferred. The alloy responds well to anodizing and other surface treatments, and it is frequently supplied with a bright, polished or brushed finish. For decorative and protective purposes, the sheet can be laminated with protective film before fabrication.
Applications of 3003 Sheet
Building and construction: roofing, siding, acoustic ceilings, corrugated sheets, gutters and downspouts are common uses, taking advantage of the alloy's corrosion resistance and formability.
Chemical and food industries: storage tanks, pipes and general metalwork benefit from the material's resistance to atmospheric corrosion and its clean, non-toxic surface.
Heating and cooling equipment: heat exchangers, air-conditioner evaporators, radiators and freezer linings use 3003 for its combination of thermal performance and workability.
Home appliances and utensils: cooking utensils, bakery moulds and appliance panels are formed from 3003 sheet, and the alloy is widely used in packaging for containers, closures and cladding.
General sheet metal: the alloy is a standard choice for ductwork, panels, brackets and fabricated parts where medium strength and easy forming are required.
FAQ
Q1: What does the O temper mean for 3003 sheet?
O is the fully annealed, soft condition. The sheet is at its most ductile state and is ideal for deep drawing and severe forming operations.
Q2: Can 3003 be heat treated to increase strength?
No. 3003 is a non-heat-treatable alloy. Strength is increased by cold working, and the strain-hardened tempers are selected when higher strength is needed.
Q3: How does 3003 compare with 5052?
5052 is an aluminium-magnesium alloy with higher strength and better saltwater corrosion resistance. 3003 is more formable and slightly less costly, and it is preferred where deep forming and general corrosion resistance are the main requirements.
Q4: What standards apply to 3003 sheet?
Common references include ASTM B209 for sheet and plate, EN 485-2 for mechanical properties and tolerances, and EN 573-3 for chemical composition. ISO 6361 also covers the alloy.
Q5: Is 3003 suitable for food-contact applications?
Yes. The alloy is widely used in cooking utensils, food storage equipment and packaging, and it is generally accepted for food contact when supplied to the applicable regulations.
Q6: What thickness range is available?
Sheet is typically supplied from 0.2 mm to 6.0 mm, with heavier plate available for structural applications depending on the supplier's rolling capability.