Compared to traditional steel, aluminum alloys, with their outstanding advantages such as lightweight and corrosion resistance, have become one of the core materials in modern marine shipbuilding. Patterned aluminum plates, in particular, play an irreplaceable role in critical areas due to their unique safety properties.
As a representative of aluminum-magnesium alloys, 5083 aluminum alloy is considered a "versatile" material in shipbuilding, especially excelling in scenarios requiring a balance between high strength and corrosion resistance. Its magnesium content is around 4%, a composition designed to create a stable metallographic structure with good weldability and machinability.
In shipbuilding, 5083 is often used in H116 and H321 tempers. These heat treatment states further optimize its mechanical properties, achieving a room temperature tensile strength exceeding 305 MPa and a yield strength exceeding 215 MPa, fully meeting the load-bearing requirements of the main hull structure.
From LNG storage tanks and GIS shells to ship hull outer shells, 5083 aluminum alloys can be found everywhere. More importantly, its density is only one-third that of steel. Using it as a structural material can reduce the ship's weight by 15%-20%, directly improving load-bearing capacity and fuel efficiency. This is also the core demand of modern ship lightweighting development.
5052 h34 marine grade aluminum is a typical representative of medium-strength alloys. Its outstanding advantages lie in its excellent resistance to seawater corrosion and high fatigue strength. The dense oxide layer formed on its surface can effectively resist salt spray corrosion. In the splash zone of Zhoushan waters, the average corrosion rate after 5 years of exposure is only 0.2 μm/a.
5086 aluminum alloy, on the other hand, focuses more on structural support. Its strength is slightly higher than 5052, and it is widely used in ship decks, engine mounts, ship sides, and bottom plating—areas that bear certain loads.
6063 aluminum alloy belongs to the aluminum-magnesium-silicon alloy family. It can be strengthened through heat treatment to obtain stable mechanical properties. It exhibits a balanced tensile strength and corrosion resistance, making it particularly suitable for manufacturing container structures on ships. The 6082 aluminum alloy in the same series has higher strength and is often used in the manufacture of internal outfitting components for ships, balancing functionality and durability.
In areas such as ship decks, walkways, and gangways, slippery environments pose a significant safety hazard. Aluminum tread plates are a key material for solving this problem. Currently, the most widely used in marine vessels is 5052 anti-slip patterned aluminum sheet.
It uses 5052 aluminum alloy as the base material and forms raised patterns such as diamond texture, orange peel texture, and five bar texture through an embossing process, giving it excellent anti-slip properties while retaining the original advantages of aluminum alloys. Different sizes like 48 x 96 aluminum diamond plate can be customized.
The high salinity of seawater and the alternating wet and dry conditions caused by tides can cause severe corrosion to metals. Aluminum alloys used in ships must pass rigorous corrosion tests. For example, the corrosion rate of 5083 alloy exposed to the marine atmosphere for 8 years must be less than 0.4 μm/a, and the mass loss from intergranular corrosion must be controlled within 15 mg/cm².
Ships endure multiple loads during navigation, including wave impacts and cargo pressure. Aluminum alloys must possess not only sufficient strength but also good toughness. Besides the 305MPa tensile strength requirement for 5083 alloy, the yield strength of aluminum alloys used in high-speed ships must exceed 300MPa. Simultaneously, key structural components must pass 10⁷ cycles of fatigue testing to prevent potential weld cracks and other hazards during long-term use.
Modern ships have complex shapes, requiring aluminum alloys to possess good plasticity. Cold forming elongation must exceed 10%, and the bending radius of the profiles must be no less than three times the thickness. Welding is a core aspect of shipbuilding; aluminum alloy welds must meet AWS D1.2 standards, with an X-ray inspection pass rate of no less than 95%. The application of advanced processes such as friction stir welding further improves weld quality and structural stability.
Any aluminum alloy material used in ships must be certified by an authoritative classification society. This is a mandatory requirement to ensure navigational safety. Whether it's CCS (China Classification Society), LR (Lloyd's Register), or ABS (American Bureau of Shipping), their certification standards cover all dimensions of indicators such as material composition, mechanical properties, and corrosion resistance. Only materials that pass the certification can enter the shipbuilding supply chain.