Because water and saltwater have a corrosive nature, special materials are required to resist these corrosive forces in the process of building assets exposed to these elements – this includes off-shore drilling platforms, shipbuilding, and more. Marine grade aluminum provides several beneficial characteristics that are ideally suitable for the construction of vessels and equipment at sea. At Howard Precision Metals, we offer an extensive array of Aluminum alloys, but don’t get much call for marine grade aluminum here in the Midwest. This blog is more about education as we consider ourselves the Aluminum experts even in alloys we may not stock.
Choosing the Right Aluminum for Near-Water Applications
Even though it may not be the best material for constant or permanent submersion, aluminum is a popular metal choice when it comes to the building of docks, ladders, pontoons, boats, and boat trailers due to its strength and lightweight characteristics. Aluminum develops an aluminum oxide coating when it is exposed to water and air that helps protect the metal against additional corrosion.
The aluminum grade chosen for marine environments is important. The 3000 series aluminum alloys are susceptible to fast oxidation. If you need an aluminum alloy that will be exposed to water or the moisture coming off the water, it is important to use a marine grade aluminum alloy, such as those in the 5000 or 6000 series. When proper maintenance and care are applied these aluminum grades can ensure a long service life for items constructed for marine purposes.
Marine Grade Aluminum Features
Although aluminum by itself, compared to many other metals, offers high corrosion resistance, it requires additional protection when exposed to water and moisture in marine applications. The alloying process combines aluminum with other metals such as magnesium to create an even stronger resistance to corrosion, making it more ideal for applications that contact water and saltwater. These types of aluminum alloys are referred to as marine grade aluminum.
Cast and Wrought Marine Grade Aluminum Alloys
Aluminum alloys are usually categorized based on the primary alloying element added to the aluminum along with the capability of the alloy to react to mechanical and thermal treatments.
Cast aluminum alloys are produced through a process which involves pouring molten metal liquid into molds of specific shapes and then cooled.
Wrought aluminum alloys are made through a process of rolling, forging, or mechanically deforming solid metals to the desired shape.
Marine grade wrought aluminum alloys often include aluminum magnesium silicone alloys and aluminum magnesium alloys. These wrought alloys of aluminum are often used for docks, boat lifts, structural shipbuilding, and other offshore structural applications.
Cast aluminum alloys are suitable for many different types of marine applications since the casting process allows for the creation of various intricate shapes, such as those for structural components, supports, interior fixtures, and a ship’s superstructure. These alloys are often aluminum silicone alloys or aluminum magnesium alloys.
5052 Alloy: High Fatigue Strength Benefits
Marine grade aluminum 5052 is a non-heat treatable aluminum alloy that possesses exceptional fatigue strength beyond most other aluminum alloys. It also provides good workability for easy forming into intricate shapes and provides solid corrosion resistance to marine saltwater and atmospheric conditions.
6061 Alloy: Workability and Corrosion Resistance
Aluminum 6061 is a highly versatile alloy for use in marine grade applications. It has excellent corrosion resistance and other mechanical properties. Under the annealed condition, it possesses solid workability and different techniques are used when fabricating this aluminum alloy. Marine grade aluminum 6061 is offered in sheet, plate, and extruded shape forms and is ideal for an array of near-water applications.
As an aluminum alloy with added silicon, grade 6061 offers superb corrosion resistance and is also easier to finish and weld than aluminum grade 5052. This alloy of aluminum is often used when extra strength is required. It is often used when workability and other properties will be helpful considering its higher cost.
6063 Alloy: Decorative and Structural Purposes
Aluminum alloy 6063 is used primarily for architectural and decorative purposes as opposed to structural support purposes. It has excellent corrosion resistance, tensile properties, and finishing characteristics. This aluminum alloy is used for various exterior and interior architectural purposes, including for trim.
Applications for Marine Grade Aluminum
Marine grade aluminum alloy is not only used for railings, docks, stairs, ladders, and other items and furnishing on or close to the water, it can also be used for storage facilities and tanks that are not specifically marine-related.
Another applicable aluminum product for marine use is aluminum honeycomb panels. These panels provide a number or advantages properties, including:
- High strength and light weight
- High impact resistance
- High rigidity
- Vibration dampening
- May be fabricated to various thicknesses
- Good insulation from sound and heat
Benefits of Marine Grade Aluminum
The various properties of marine grade aluminum alloy that make it ideal for marine conditions include:
- Excellent resistance to corrosion due to saltwater exposure
- Very lightweight with an excellent strength-to-weight ratio
- Offered in multiple grades, plates, sheets, and extrusions
- Usable with various fabrication procedures
For information about the marine grade aluminum alloy products we offer at Howard Precision Metals, give us a call at 800.444.0311 or request a quote today.
