Pure aluminium sheet
Pure aluminium sheet (often called high-purity aluminum or commercially pure aluminium sheet) is a widely used form of aluminium for industries that require excellent corrosion resistance, thermal and electrical conductivity, formability, and a clean metallic appearance.
Table of Contents
- What is Pure Aluminium Sheet?
- Functions and Material Advantages
- Common Applications
- Chemical Composition (Typical Grades)
- Alloy Temper and Heat Treatment Conditions
- Mechanical & Physical Properties
- Technical Specifications & Parameters
- Manufacturing & Processing Methods
- Surface Finishes and Treatments
- Implementation Standards and Certifications
- Inspection, Testing, and Quality Control
- Handling, Storage, and Fabrication Tips
- Conclusion
- References / Common Standards
What is Pure Aluminium Sheet?
Pure aluminium sheet generally refers to aluminium products with very high aluminium content and minimal alloying elements. Commercially pure aluminium is often referred to by series numbers such as 1050, 1060, 1100 (in the 1xxx series), where the last two digits indicate minimum aluminium percentage beyond 99%. These sheets offer excellent ductility, corrosion resistance, electrical and thermal conductivity, and are easy to form and weld.
Functions and Material Advantages
- Excellent corrosion resistance in many environments, including atmospheric and many chemicals.
- High electrical and thermal conductivity (close to that of copper per mass basis).
- Superior formability and ductility, enabling deep drawing, bending, and spinning.
- Non-magnetic and non-sparking — useful for specialized environments.
- Lightweight — low density (≈ 2.70 g/cm³), beneficial for weight-sensitive applications.
- Good reflectivity for thermal and visible light — suitable for reflective surfaces and heat shields.
- Recyclable and environmentally friendly (high recyclability rate with low energy cost relative to primary production).
Common Applications
- Electrical: busbars, conductors, transformer fins, capacitor housings.
- Packaging: foil lamination backings, food packaging, pharmaceutical packaging substrates.
- Construction: cladding, roofing, soffits, flashing, gutters, and facades.
- Transportation: body panels, fuel tanks (non-ferrous requirements), heat exchangers.
- Consumer goods: cookware, kitchen appliances, lighting reflectors.
- Industrial: chemical equipment linings, heat exchangers, HVAC components.
- Forming/Deep Drawing Products: beverage cans (in different aluminium forms), utensils, utensils components.
- Specialized: cryogenic equipment and vacuum vessels (where pure aluminium's ductility at low temperatures is beneficial).
Chemical Composition (Typical Grades)
The 1xxx series are essentially "pure" aluminium grades with minimal alloying elements. Below are typical compositions for commonly used pure aluminium sheet grades.
| Element / Grade | 1050 (Al99.5) | 1060 (Al99.6) | 1100 (Al99.0+) |
|---|---|---|---|
| Aluminium (Al) | 99.50% min | 99.60% min | 99.00% min |
| Silicon (Si) | 0.25% max | 0.25% max | 0.95% max |
| Iron (Fe) | 0.40% max | 0.35% max | 0.95% max |
| Copper (Cu) | 0.05% max | 0.05% max | 0.05% max |
| Manganese (Mn) | 0.03% max | 0.03% max | 0.05% max |
| Magnesium (Mg) | 0.03% max | 0.03% max | 0.03% max |
| Zinc (Zn) | 0.05% max | 0.05% max | 0.10% max |
| Titanium (Ti) | 0.03% max | 0.03% max | 0.03% max |
| Others (each) | 0.03% max | 0.03% max | 0.05% max |
| Others (total) | 0.15% max | 0.15% max | 0.15% max |
Note: Exact chemical limits vary by specification and standard (e.g., ASTM, EN). Check specific mill certificates for exact composition.
Alloy Temper and Heat Treatment Conditions
Pure aluminium in the 1xxx series is not heat-treatable (strength is not improved by heat treatment). Strength and properties are controlled by tempering through cold work (strain-hardening) and annealing.
| Temper Designation | Description | Typical Condition |
|---|---|---|
| O (Annealed) | Fully annealed, maximum ductility | Annealed at ~350–420°C (controlled) followed by slow cooling |
| H111 | Slightly strain-hardened after shaping | Cold working less than H11 |
| H11 | Strain-hardened by cold work | Low degree of cold work |
| H12 | Half-hard (higher cold work) | Moderate cold work |
| H14 | Quarter-hard | More cold work; increased hardness/strength |
| H16 | Hard | Higher cold work; used where higher strength required |
Notes:
- "O" temper has the lowest strength and highest formability.
- H-temper numbers vary: H12, H14, H16 are common for sheet/strip; H24, H26 are tempers with controlled partial anneal, etc.
- Exact mechanical properties depend on thickness and processing.
Mechanical & Physical Properties (Typical)
Typical properties for commercially pure aluminium (e.g., 1050, 1100) in different tempers. Values are approximate; verify per supplier.
| Property | O Temper (Annealed) | H14 (Quarter-hard) | Units |
|---|---|---|---|
| Density | 2.70 | 2.70 | g/cm³ |
| Tensile Strength (Rm) | 70–105 | 95–150 | MPa |
| Yield Strength (Rp0.2) | 20–40 | 40–70 | MPa |
| Elongation (A50) | 20–45 | 6–22 | % |
| Electrical Conductivity | ~61–62 | ~60 | % IACS |
| Thermal Conductivity | 220–235 | 220–235 | W/m·K |
| Modulus of Elasticity | 69 | 69 | GPa |
| Melting Range | 660–660.5 | 660–660.5 | °C |
| Hardness (Brinell) | 15–25 | 25–35 | HB |
Notes:
- 1xxx series have lower strengths compared to alloyed series but have superior formability and conductivity.
- Conductivity measured as percentage of International Annealed Copper Standard (IACS) — values depend on purity and temper.
Technical Specifications & Parameters
| Parameter | Typical Range / Value | Remarks |
|---|---|---|
| Thickness | 0.1 mm – 8.0 mm (sheets/foils) | Foils below 0.2 mm; thicker plates defined separately |
| Width | Up to 2000 mm or wider for jumbo coils | Cut-to-size service available |
| Length | Coils or cut lengths; custom | Coil inner diameters and lengths per mill |
| Surface Finish | 2B (mill), BA (bright annealed), mirror, brushed, patterned | For decorative or functional finishes |
| Flatness | Per specification (e.g., EN 485 or ASTM) | Important for cladding applications |
| Edge Condition | Slit, shear cut, deburred | Depends on customer needs |
| Coating Options | Anodized, PVDF, paints, laminates | Improve corrosion resistance and aesthetics |
| Tolerances (Thickness) | ±0.02–0.15 mm depending on thickness | Per EN 485 / ASTM B209 equivalents |
| Packing | Pallets, wooden crates, protective film | For export and long-haul shipping |
Manufacturing & Processing Methods
- Primary manufacturing: rolling (hot rolling then cold rolling) to achieve desired thickness and surface finish.
- Annealing: controlled annealing in continuous or batch furnaces to achieve O temper.
- Cold working: mechanical rolling, bending, or drawing to achieve H tempers.
- Surface processing: chemical cleaning, mechanical polishing, anodizing, painting, and laminating.
- Joining: welding (TIG/MIG), brazing (with appropriate filler), adhesive bonding, riveting.
Surface Finishes and Treatments
| Treatment | Purpose | Typical Methods |
|---|---|---|
| Mill finish (2B) | Standard surface after rolling | Light rolling and cleaning |
| Bright Anneal (BA) | Improved reflectivity | Anneal in protective atmosphere |
| Anodizing | Corrosion resistance, decorative | Sulfuric or chromic acid anodizing |
| Coating (PVDF) | Weather resistance and color | Coil coating or post-coat |
| Polishing/Brushing | Decorative/functional reflectivity | Mechanical finishing |
| Protective Film | Scratch protection | Temporary polyethylene film |
Implementation Standards and Certifications
Pure aluminium sheet is produced and tested to many international standards. Common standards include:
- ASTM B209 — Standard Specification for Aluminium and Aluminium-Alloy Sheet and Plate.
- ASTM B210 — Aluminium and Aluminium-Alloy Drawn Seamless Tubes (relevant for other forms).
- EN 485-2 — Aluminium and aluminium alloys — sheet, strip and plate — mechanical properties.
- EN 573-3 / EN 573-1 — Chemical composition and designation of aluminium alloys.
- EN 755 / EN 10204 — For extrusion and product testing documentation.
- ISO 9001 — Quality management systems for manufacturers.
- RoHS / REACH — For hazardous substances control (where applicable).
Always request mill test certificates (MTC) verifying chemical composition and mechanical properties per order.
Inspection, Testing, and Quality Control
Common quality tests for pure aluminium sheet:
- Chemical analysis (OES/ICP) to confirm alloy composition.
- Mechanical testing — tensile, yield, elongation.
- Hardness testing — Brinell or Vickers.
- Dimensional checks — thickness, width, flatness.
- Surface quality inspection — visual, coating adhesion.
- Conductivity testing — electrical conductivity measurement.
- Non-destructive testing (as required) — eddy current, ultrasonic for thicker plates.
Handling, Storage, and Fabrication Tips
- Store in dry, ventilated areas; protect with films to prevent surface damage.
- Avoid contact with dissimilar metals unless corrosion protection is applied — bimetallic corrosion may occur in certain environments.
- Use proper lubrication for forming operations to avoid galling.
- For welding, use clean surfaces; pure aluminium requires appropriate weld parameters and filler metals (often ER4043 or ER5356 depending on requirements).
- For anodizing, ensure chemical cleaning and de-smutting to meet finish quality.
- Avoid sharp folds when deep drawing very thin gauge pure aluminium to prevent cracking — choose appropriate temper.
