Aluminum Extrusions for Military Marine Application
With all the possibilities of technical advancement, there are endless ways to be innovative these days. With that in mind, what is the significance of technology and innovation in shipbuilding? We can go back to the American Civil War in 1862, wherein two ironclad warships battled for the first time. Not one ship sunk; thus, both parties claimed victory.
For naval technology, this was an important milestone. Why? Because ironclad warships had shown an increase in survivability compared to their wooden-hulled predecessors. Presently, the battlefield is evolving faster than ever and the need has emerged for a new breed of warships with increased speed, agility, and stealth.
Look no further! The answer is aluminum.
5xxx aluminum alloys
Aluminum allows vessels to be made lighter and faster at one-third the density of steel. The corrosion resistance and strength of new alloys, especially the 5xxx series of aluminum alloys, make it an ideal choice for constructing sea-going vessels. Adding elements to pure aluminum produces a chemical composition with improved properties creating an aluminum alloy that increases strength. A 4-digit number is then assigned in which the first digit represents a general series that characterizes its main alloying elements.
The primary agent for the 5xxx series is magnesium which gives the alloy strength and good weldability, amongst other things. In naval ships alone, 6,000 tons of aluminum are used each year on destroyers. For more than a decade now, 5456 plate and extrusions have become the benchmark for the welded deckhouse structures of destroyers. The weight-saving ability of the 5xxx series allows the ship to maintain stability with a narrow hull that is crucial in reaching high speeds.
Advantages of 5xxx aluminum alloys
The structures save 55-67% of their weight by using a 5xxx aluminum alloy. The ships can increase payload, haul more equipment, and lower the energy required to power the boat. The 5xxx series has good weld ductility without post-weld treatments due to the weld yield strengths of 100-200 MPa. It has lower corrosion resistance which is ideal for any structure encountering water or chemicals. The tensile strength of the alloy showed reductions of only 2-5% throughout a 10-year seawater test.
Friction stir welding for marine vessels
The growth of new metal forming processes, friction stir welding (FSW) chief among them, has made aluminum one of the most versatile materials, creating profiles. For more than twenty years, friction stir welding or FSW has been a highly effective alternative to traditional MIG welding in marine applications. It is best used on long straight welds for a more cost-effective and efficient operation.
Several of the welded structures in this process are alloyed aluminum extrusions. Flat designs used in the marine industry, such as floors, decks, bulkheads, and parts that do not require complex curves, can be done by FSW. These vessels are capable of speeds of more than 45 knots (51 mph), an exceptional rate for vessels that weigh 3,500 tons. Even hull sections are critical to making the vessels lighter, faster, and more maneuverable.
Benefits of friction stir welding for marine vessels
Speeds up the building procedure and saves money for large and small projects.
The cost savings come from eliminating the required person-hours of traditional MIG welding and providing a more substantial, higher quality weld, which cuts down on secondary repair costs. Using complete components such as modular FSW panels reduces the time and labor costs of measurements and cutting on the construction site. There is also minimal distortion on the weld and better aesthetics. It is more environmentally friendly (no UV radiation or fumes) and more user-friendly.
Removes flaws that are inherent to conditional welding methods.
Characteristics include no porosity, no hot cracking, and a more robust fusion of the constituent elements. Becoming adopted far and near, FSW is less susceptible to errors due to the automated process.
Aluminum can help marine manufacturers and shipbuilders obtain weight and production savings and improve the quality and efficiency of vessels and structures… and the unique qualities of extruded aluminum component design provides exceptionally high torsion strength resistance – making it the ideal material for marine application.
More About Taber Extrusions
Taber Extrusions, founded in 1973, originally pioneered a process for extruding extra-large aluminum extrusion profiles up to 31 inches wide or hollows up to 29 inches. Taber expanded with the purchase of an extrusion facility in Gulfport, MS, in 1995. It houses a state-of-the-art cast house and two additional presses, microextrusion capabilities, and the fabrication area, which has been expanded multiple times.
Taber continues to extrude billet in a wide range of alloys and sizes. It also has diversified its markets beyond the military since its inception to include aerospace, automotive, marine, infrastructure, and sporting goods, among many others. With in-house casting solutions, ultra-precision extrusion manufacturing, friction stir welding capacities, and a full range of hard and soft aluminum alloys, Taber aligns itself as an industry leader in having the broadest available capabilities.
Today, Taber Extrusions is proud of its recently added VF-12 CNC machining line and a complete offering of extruded aluminum components, value-added machining services, and raw material supply to the North American market. Adding these capabilities to a growing portfolio drives Taber into the future in a pursuit to continuously enhance the quality and service we provide to our customers.
We appreciate your ongoing support of Taber Extrusions, LLC. If you have any questions, please visit taberextrusions.com or reach out to one of Taber’s regional sales managers.
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