Cold-rolled oxidized aluminum plate

1. Material Definition and Process Flow

Cold-rolled oxidized aluminum plate is made from aluminum ingots throughCold rolling process(below recrystallization temperature) andAnodizingHigh-performance composite material combining the mechanical properties of a metal matrix with the protective characteristics of an oxide layer.

2. Core Production Process

Cold Rolling Process (1)

• Temperature ControlRolling temperature is controlled below the recrystallization temperature (approximately 250–400°C) to prevent grain coarsening.

• Rolling methodUses single-stand or multi-stand continuous rolling (e.g., three-high mill). Plate thickness is reduced through multiple passes with a total reduction of 5–30%, achieving a final thickness of 0.1–3 mm.

• AnnealingAfter rolling, perform low-temperature annealing at 150–200°C to relieve internal stresses and restore material ductility.

Anodizing (2)

• Electrolyte: Use common sulfuric acid (density 1.8–2.0g/cm g/cm³) or oxalic acid solution at voltage 12–24 V and temperature 15–20°C.

• Film formationAluminum serves as the anode and undergoes oxidation in the electrolyte to form a dense, porous aluminum oxide film (3–10 μm thick).

• Post-processing：

  • Clean: Remove residual electrolyte from the surface.

  • SealSeal micropores with boiling water or organic solvents to enhance corrosion and weather resistance.

3. Key Performance Indicators

- 热膨胀系数：23.1×10⁻⁶/℃  
- 密度：2.7 g/cm³  
- 硬度：HV 500–1500（氧化膜硬度达宝石级）

| Chemical Properties| - Corrosion Resistance: Passes GB/T 9278 salt spray test (≥2000 hours)
- Acid & alkali resistant: stable within pH 2–12
- Self-cleaning: Low surface electrostatic attraction, resists dust accumulation |
| Machinability| - Bend radius: ≥1.5t (t = sheet thickness)
- Formability: Can form complex structures in a single step
- Weldability: Suitable for TIG/MIG welding |

4. Structure and Function of the Oxide Film

• microstructure: The oxide film has a hexagonal honeycomb porous structure with pore diameters of approximately 50–100 nm and a porosity of 30–40%.

• Features：

  • Corrosion-resistantThe dense coating prevents electrolyte penetration and offers strong resistance to chloride ion corrosion.

  • WeatherabilityMaintains color stability for over 10 years in outdoor use (UV absorption rate > 90%).

  • Insulation: Volume resistivity > 1 × 10¹⁴ Ω·cm, suitable for electronic packaging.

5. Typical Application Areas

(1) Premium Construction Sector

• Curtain Wall SystemUltra-thin cold-rolled oxidized aluminum plate (0.8–1.2mm) for modern building facades, combining lightweight design (only 1/3 the weight of glass) with high strength (wind pressure resistance ≥4kPa).

• Decorative PanelAchieves metallic finishes in gold, silver, and more via PVD coating technology for premium interior decor.

(2) Precision Industrial Manufacturing

• Electronic Components: PCB substrates and chip carriers, leveraging high insulation and thermal dissipation.

• Semiconductor Equipment: Cavity wall material, resistant to high-temperature plasma corrosion (temperature ≤ 800°C).

(3) Special Scenario Requirements

• Aerospace: Satellite antenna reflectors and spacecraft thermal insulation layers, withstand extreme temperature fluctuations from -270°C to +300°C.

• Medical Cleanroom: Surface antimicrobial coating (with silver ions), meeting ISO 14644-1 Class 5 cleanliness standards.

6. Technology Trends

1. nanometer-scale oxide film: Prepare nanoscale oxide films (<50 nm) via pulse plating to enhance wear resistance and optical performance.

2. Functional CoatingsDevelop conductive oxide films (ITO), self-healing coatings, and other technologies to expand application boundaries.

3. Green Technology: Utilize low-temperature acid-free oxidation techniques (e.g., plasma oxidation) to reduce energy consumption and environmental pollution.

7. Competitive Advantages

Cold-rolled oxidized aluminum plate passesMaterial InnovationandProcess Optimizationhas become a core material in high-end equipment, precision electronics, and green building sectors, with its technological evolution continuing to drive transformation and upgrading across multiple industries.