Friction Stir Processing (FSP) for Shipbuilding Quality Welds
Friction Stir Processing to Improve Formability & Fatigue Life
Friction Stir Welding is a Game Changer for Aluminum Shipbuilding
Shipbuilding with aluminum for lighter weight, more speed, and dramatically lower construction costs is evolving at a rapid pace. Welding technology no longer has a limited number of fusion welding processes available, but now has Friction Stir Processing (FSP) available which is perfect for shipbuilding. Longer automated panel welds, lower costs, modular kit methodology, and higher quality are all directly related to Friction Stir Welding.
In Friction Stir Processing (FSP), the melting of fusion welding is replaced with localized plastic deformation with the tool’s stirring motion as the weld bead moves laterally past it. There is still a heat-affected zone, but the metallurgic properties are improved. The materials phase is never changed resulting in a microstructure of fine grains. Improved formability, tensile strength, fatigue strength (life) are the primary results. All of these physical properties make Friction Stir Processing the current process of choice for all aluminum shipbuilding.
Bayou Manufacturing is a leader in bringing Friction Stir Processing (Welding) into the modular shipbuilding capabilities in the USA.
Presently, prevailing aluminum ship construction is limited aluminum plates or sheets to be formed to a minimum of a 2.5T bend radius through an angle of 90° degrees in a press brake. Cracking is more prevalent when formed parallel to the rolling direction; therefore, press brake forming of the flange is usually done transversely to the direction of rolling. To obtain long length flange members, several sheets must be joined to honor the forming of the sheet transverse to the rolling direction. This results in extra cost and distortion from the weld seams by joining standard width sheets for transverse bending to obtain long flange member lengths. Cracking nevertheless occurs, unless the part is pre-annealed by heating. If there is cracking, it is repaired by arc welding which also anneals the part.
This novel process, now 30 years in development, offers significant improvement in other areas including:
- Welding difficult to weld materials
- Application to plastics and other non-traditional materials
- Modification of surfaces and fabrication of surface composites for layered material properties
- Ability to weld advanced aluminum allows for the aerospace industry with excellent mechanical properties not possible with fusion welding techniques
The Expertise to be Your Shipbuilding Partner
Bayou Manufacturing is a leader in bringing Friction Stir Processing (Welding) into the modular shipbuilding capabilities in the USA. Our wide range of projects from the Staten Island Ferries, to the USCG OPV and multiple US Navy shipbuilding programs gives Bayou the clear advantage in FSP expertise, engineering capability, size of production line, and modular shipbuilding kits. Our ability to deliver highest quality, lowest cost, and superior project management make Bayou a valuable shipbuilding partner.