In the vast ocean, ship containers must not only withstand the internal pressure of their contents but also resist the harsh corrosion of the external marine environment. The choice of material directly affects the service life and maintenance costs of the containers.

Traditional materials, such as ordinary steel, offer high strength but are heavy and prone to corrosion, which increases fuel consumption and maintenance frequency for ships.

In contrast, 6063 aluminum plate stands out in this field thanks to its well-balanced performance.

What is 6063 Aluminum Plate?

6063 aluminum alloy belongs to the Al-Mg-Si series of heat-treatable alloys. It features excellent workability, outstanding weldability, and good corrosion resistance. With a density of approximately 2.69 g/cm³, which is only about one-third that of steel, 6063 aluminum provides significant weight reduction advantages for ship design.

After heat treatment, 6063 marine aluminum plate achieves excellent mechanical properties, physical properties, and corrosion resistance, making it ideal for marine container structures.

Anodized Marine Aluminum Plate

To extend the service life of ship containers in harsh marine environments, 6063 aluminum plates can undergo surface treatments, such as anodizing.

Anodizing not only enhances corrosion resistance but also allows for different color finishes, which helps with container classification and improves appearance.

Performance Advantages of 6063 Aluminum Plate

(1) Corrosion Resistance

6063 aluminum alloy offers excellent corrosion resistance thanks to the protective oxide film that naturally forms on its surface.

Research indicates that even in seawater environments containing Hg²⁺ ions, when the Hg²⁺ concentration is below 0.5 μg/L, the corrosion rate of 6063 aluminum alloy does not exceed 20 μm/a. At concentrations between 0.5 and 15 μg/L, the corrosion rate generally remains between 20-35 μm/a.

(2) Processability

6063 aluminum alloy has excellent thermoplasticity and can be extruded at high speed into complex, thin-walled, hollow profiles. This makes it possible to manufacture marine containers in various shapes and specifications.

It also has excellent welding performance and no tendency for stress corrosion cracking - among heat-treatable aluminum alloys, the Al-Mg-Si series is the only one in which stress corrosion cracking has not been observed.

Additionally, after processing, 6063 aluminum offers a smooth surface that is easy to anodize and color, making it highly suitable for ship container applications.

(3) Mechanical Properties

6063 aluminum plate features high plasticity and tensile strength, with strong deformation resistance. Its hardness is relatively high, ensuring that containers are not easily deformed or cracked, which helps keep stored liquids safe.

According to technical data, 6063-T5 aluminum plate has a tensile strength in the range of 130-230 MPa, a yield strength of 55.2 MPa, and an elongation of 25.0%. These mechanical properties ensure structural integrity even under complex marine conditions.

Specific Applications of 6063 Aluminum Plate in Ship Container Structures

Given its balanced properties, 6063 aluminum alloy is mainly used in non-load-bearing structures and containers that prioritize light weight, ease of processing, and corrosion resistance over high strength, such as:

(1) Non-Pressure Containers and Storage Tanks

• Freshwater and wastewater tanks: Thanks to its good water corrosion resistance, 6063 is often used to make onboard freshwater and wastewater storage tanks.

• Fuel/Lubricating oil tanks (non-pressure): Suitable for storing light fuels or lubricants in auxiliary tanks.

(2)Superstructure Auxiliary Frameworks

6063 aluminum is used in window and door frames, railings, ventilation ducts, and cabin partition panels. These components mainly bear their own weight and wind pressure. 6063 provides sufficient strength while reducing the weight of the superstructure, improving the ship’s stability and fuel efficiency.

(3)Interior and Outfitting Components

6063 aluminum is also used in furniture, decorative panels, cable trays, and various support structures inside cabins. Its excellent surface finish and anodizing capability make it ideal for interior fittings.

Comparison with Dominant Marine Alloys

In shipbuilding, the selection of aluminum alloys is cautious and based mainly on strength and seawater corrosion resistance. As a result, 5xxx series alloys (e.g., 5083, 5086) and high-strength 6xxx series alloys (e.g., 6061) dominate ship structures.

5083 marine aluminum plate, with its higher magnesium content, offers very high strength and excellent seawater corrosion resistance, making it the preferred material for hulls, decks, and other primary load-bearing structures.

6061 marine aluminum plate combines high strength with good weldability, making it suitable for beams and load-bearing frameworks.

In comparison, 6063 aluminum plate has medium strength. While it provides good resistance to atmospheric and freshwater corrosion, its resistance in high-salinity marine environments is lower than that of 5xxx series alloys. Nevertheless, its light weight, good processing performance, and surface treatment versatility make it a cost-effective choice for secondary marine container structures.