Microstructural Development in Friction Stir Welding
Abstract
Friction stir welding (FSW) is a relatively new technique for joining metals. It uses a rotating tool to deform ("stir") the surrounding material together without any melting. Although FSW was only developed in 1991, it is already experiencing a rapid growth in applications because of its ability to consistently produce high quality welds with low distortion, even in materials considered "unweldable" by conventional techniques. In addition, the accompanying reductions in weld inspection and re-weld procedures can also provide significant cost benefits. However, despite this considerable interest in FSW, the microstructural evolutions occurring during FSW are still not well understood. Conventional studies typically examine only sections of the deposited weld, then use those observations to infer the processes that gave rise to those microstructural features. We have instead examined the microstructural evolution at its source-around the FSW tool. We have prepared a stop-action weld in Al-Li 2195 by interrupting the welding process and quenching the weld with cold water to "freeze in" the dynamic processes surrounding the tool and permit an analysis of the actual grain evolution and texture development occurring around of the FSW tool.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA521602
Entities
People
- J. F. Bingert
- K. J. Colligan
- R. W. Fonda
Organizations
- United States Naval Research Laboratory