Over the last two decades, friction stir-welding has emerged and been established as an extremely effective alternative to traditional MIG welding for use in marine applications, particularly as the industry moves towards increased use of aluminum. The powerful combination of reduced weight from aluminum and increased strength of FSW welds can yield spectacular benefits for marine designs.
Aluminum can help you obtain weight and production savings and improve the quality and efficiency of your vessels and structures. Aluminum reduces weight without sacrificing structural strength. The unique qualities of extruded aluminum component design provides you with exceptionally high torsion strength resistance.
If you’re looking to cut costs of construction for your cruise ships, mega-yachts, defense vessels, passenger ferries, leisure craft, as well as offshore platforms and rigs, read on!
FSW is Well Suited For Marine Applications Because of The Nature of The Welds
The friction stir welding process is best utilized on long straight welds, as this allows for a more cost-effective and efficient process. Unsurprisingly, this happens to cover a significant portion of the flat structures that are used in the marine industry, such as floors, decks, bulkheads, and more parts that don’t require complex curves. Many of the structures that are welded in this process are alloyed aluminum extrusions.
Friction-stir welding is a great compliment to alloyed aluminum as it can successfully weld any of the normal range of aluminum alloys – whether that be the plate, extruded sections, forging, or castings – including high strength alloys such as 7xxx and 2xxx series aluminum. The ability to weld dissimilar materials effectively (for example, steel to aluminum) is an additional benefit of FSW.
Benefits of FSW For Marine Vessels
For projects both large and small, the FSW process stands to speed up the construction process and save money. The cost savings comes from the elimination of the required man-hours of traditional MIG welding, and also provides a stronger, higher quality weld, which cuts down on secondary repair costs down the line. Also, using complete components such as Modular FSW panels reduces the time and labor costs of measurement and cutting on the construction site.
Minimal distortion on the weld, and better aesthetics
More environmentally friendly (no UV radiation or fumes) as well more user-friendly
Removes flaws that are inherent to conditional welding methods – no porosity, no hot cracking, stronger fusion of the constituent elements
FSW is becoming more widely adopted and is less susceptible to errors due to the automated process
Founded in 1973, Taber Extrusions originally pioneered a process for extruding rectangular billet which enables the company to extrude solid 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 which houses a cast house and two additional presses, and multiple expansions of value added fabrication services. Taber continues to extrude billet in a wide range of alloys and sizes, including 7″billet molds, and has diversified its markets beyond military since its inception to include aerospace, automotive, marine, infrastructure, and sporting goods, among many others. For these markets, the company supplies extruded products in a variety of soft and hard alloys. In 2018, Taber added ultra-precision extrusions to their capabilities allowing them to further serve customers in electronics, computer, and medical industries. Today Taber is proud to announce yet another exciting launch into Friction Stir Welding.
Taber is AS9100, NADCAP, and ABS certified. Founded in 1973, Taber Extrusions originally pioneered a process for extruding rectangular billet which enables the company to extrude solid 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 which houses a cast house and two additional presses, and multiple expansions of value added fabrication services.
Taber continues to extrude billet in a wide range of alloys and sizes, including 7″ billet molds, and has diversified its markets beyond military since its inception to include aerospace, automotive, marine, infrastructure, and sporting goods, among many others. For these markets, the company supplies extruded products in a variety of soft and hard alloys. In 2018, Taber added ultra-precision extrusions to their capabilities allowing them to further serve customers in electronics, computer, and medical industries. Today, Taber is proud to announce yet another exciting launch into Friction Stir Welding.
The applications for aluminum alloys are varied, but for many projects, such as with infrastructure or medical products, the appearance of the final product counts. This means that having a variety of aluminum surface finishes creates more possibilities for what an aluminum extrusion can do. We will review what surface treatments provide and the different types of finishes available in the industry.
What advantages do aluminum surface treatments provide?
Often just seen as a means of corrosion protection, these treatments can drastically impact a variety of conditions and properties. Such changes include:
Altering surface hardness and abrasion resistance
Coating adhesion like paints, varnish, and bonding adhesives
Providing protection from corrosion and durability
What types of aluminum surface finishes are there?
No matter the application, aluminum and its alloys provide the advantage of having a naturally hard and inert surface oxide layer. This layer is formed in aerated water and air and then re-forms when the metal is cut. Subsequently, the oxide film allows aluminum and its alloys to have minimal corrosion.
The surface finishes for aluminum fall into three main groups: anodizing, powder paint and liquid paint. Though not as common, there are other surface finishes which include mechanical finishes, pretreatment, and sublimation.
The Big Three: Anodizing, powder coating, and wet coating
Anodizing – Adding further protection beyond the natural oxide film, this electrochemical process provides durability to the aluminum. Anodized aluminum can accept vibrant colors and any aluminum alloy can be anodized.
Powder Paint– This process leaves behind a film that meets intense performance criteria. For example, there are many environmental regulations that prevent the use of VOCs which powder coating does not contain. It is applied as a solid, and when going through and over, the solid particles fuse to form the film.
Liquid Paint – Varying in color, this film provides uniform thickness. Unlike powder coating, they do contain VOCs but they are driven off during the baking process. When these VOCs are removed, the volume solids form a film on the extrusion.
Other aluminum surface finishes:
Mechanical finishes – Aluminum and aluminum alloys can be buffed, polished, blasted, sanded, or grinded. This is typically done in order to improve the surface quality of the extrusion in order to prepare it for further cosmetic finishes.
Pretreatment – This surface finish is done by either etching or cleaning the profile with alkaline or acidic materials. Following the cleaning, a pretreatment coating is applied which enhances paint or powder adhesion, thus providing stronger resistance against corrosion.
Sublimation – This technique is rarely implemented but is becoming more common over time. Sublimation makes an aluminum alloy look like wood of all things! First, a base coat of powder is applied and then the extrusions go through sublimation. Then technicians place a thin film with a pattern on it around the profile. With the sublimation process, the wood pattern is directly transferred onto the extrusion.
Taber Extrusions knows what it takes to produce the top-quality extrusions with the best possible finishes. We offer a variety of surface finishes and work closely with our customers to achieve products that are not only reliable and functional but good looking.