Joining Aluminum Extrusions Through Friction Stir Welding
What is Friction Stir Welding?
Friction stir welding is the method of joining two pieces of metal with no extra filler or material by subjecting the components to heavy plastic deformation, at elevated temperatures, that are still lower than the melting point. A rotating tool is thrusted between the components and, as friction heat is generated, the tool produces a severe plastic deformation under high pressure, at which time the weld interfaces are stirred together, and a homogenous structure is formed, creating a defect-free bond.
Why Friction Stir Welding?
FSW is a method of welding that is being used as an alternative method to fusion welding and other types of arc welding.
FSW vs. Fusion Welding – FSW offers three key benefits over fusion welding: metallurgical, environmental, and energy. The metallurgical benefits include: low distortion of workpiece (fine microstructure, absence of cracking), good dimensional stability, and no loss of alloying elements. The environmental benefits include: no shielding gas required, no surface cleaning required, elimination of solvents required for degreasing, and consumable materials savings. The energy benefits include: improved material use (joining different thickness), only 2.5% of energy needed for a laser weld, and decreased fuel consumption in light weight, automotive, and ship applications. FSW is then, specifically because of its environmental and energy benefits, a more cost-effective method of welding. It is also a more economical choice due to low set up and training costs.
FSW vs. Other Types of Arc Welding – The joining of aluminum extrusions in friction stir welding is a process that can be easily automated, making it an ideal solution for industrial use in manufacturing services such as the marine, aerospace, automotive, transportation, and rail industries. FSW welds have effectively been used in the marine industries in the fish freezer panels of ships, on the deck panels of helicopter landing platforms on ships, and it has been used in various amphibious assault ships. In aerospace, FSW has been used for structures such as the fuselage, fins, and wings that require high-strength aluminum alloys. In the automotive industries, FSW is used for aluminum engine cradles and suspension struts, as well as rear seats and exhaust gas recirculation coolers. The railway industry has utilized FSW to make roof and floor panels, as well as heat sinks for cooling the high-power electronics of locomotives.
In military and defense, aluminum alloys are used as armor due to the combination of high ballistic performance and static strength that traditionally use MIG, gas metal arc, and tungsten arc welding. The reasons for the transition to FSW over the aforementioned arc welds are many — MIG welds cause stress corrosion at the weld toe, exfoliation occurring in the solution treatment, low ductility in butt welds, and liquidation due to the formation of low-melting point grain boundary. FSW welds are also more likely to pass the ballistic shock test.
Why FSW at Taber? New Aluminum Joining Techniques at Taber
In April of 2019, Taber Extrusions of Russellville, AR and Gulfport, MS announced the addition of Friction Stir Welding, “FSW,” capabilities to our existing portfolio which currently includes aluminum extrusions, fabrication, billet casting, and micro-extrusions. With the addition of in-house FSW capabilities, Taber is now a vertically integrated supplier of FSW panels and assemblies.
Taber’s engineering and manufacturing teams collaborated with Bond Technologies to create a custom Linear Seam machine. Taber’s new FSW machine is capable of welding large, double-sided thick profiles with minimal cycles of the machine; less cycles means greater efficiency and more precise results.
Taber offers quality custom extrusion design and advanced microextrusion capabilities and we are committed to providing our clients durable products that are both ecologically sound and cost effective. We chose FSW as a high-tech, alternative method to ensure a fast turn-around time, thereby reducing time to market.
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.