SBIR-STTR Award

Friction Stir Welding (FSW) has been demonstrated to provide significant benefit for Naval applications. However, its use has been limited to fabrication of panels, because no portable multi-axis FSW solution exists. If FSW could be used for in situ fabrication of complex assemblies, significant further benefits could be realized, including cost reduction and improved quality (significantly less distortion). However, there are technical challenges that must be solved to be able to realize this use of FSW. One of the most significant technical challenges, which will be addressed in this project, is to develop a system that is capable of managing the significant variation (part location, gaps, mismatch, etc.) that occurs in this application. A flexible, adaptable, and portable solution is required which maximizes manual control and simplifies setup and breakdown. One other important area of development which will be addressed is to reduce the forces required to perform FSW. This will help improve the chances of implementation of a portable FSW solution.

Keywords:
Fsw, Portable, Flexible, Adaptable, Force, Robot, Multi-Axis

In Phase I, technical and commercial feasibilty has been demonstrated for low force FSW processes that could be implemented onto a flexible and portable robotic system. The processes were implemented on a standard industrial robot, which could be integrated into a portable FSW system for fabrication of aluminum modules for ship superstructure. Two approaches were demonstrated, including a low force standard FSW process for welding 5xxx alloys and a self-clamping, self-reacting process. In addition, potential designs were shown that could enable FSW to be used for various assembly operations, including assembly of modules. This would allow FSW to be used throughout the shipbuilding process and not just for panel fabrication, allowing the benefits of FSW to be realized throughout the assembly process. Phase II seeks to further develop the low force processes, by continuing research and develompment to optimize the processes. Production capable processes will be developed. In addition, hardware and software development will occur to allow integration of a flexible, but yet portable robotic FSW system capable of adapting to the variation that is inherent in ship construction. A complete system will be integrated to demonstrate the ability to fabricate wide panels, attach stiffeners and girders, attach corners, and assemble panels into modules. A typical module used on a Littoral Combat Ship will be fabricated for demonstration purposes.

Keywords:
Aluminum, Low Force, Module Assembly, Portable, Flexible, Friction Stir Welding,