Local property characterization of friction stir welded Ti-5111: Transverse orientation measurements

Friction stir welding (FSW) provides many advantages over traditional joining techniques, the most significant of which is lower cost of fabrication. Titanium alloys provide a high specific strength and increased corrosion resistance, which makes them an attractive material for use in extreme environments, such as those experienced by the next generation vehicle systems - marine, air, land or space. This research is focused on understanding the local mechanical properties and microstructure of a friction stir weld of a 12.7 mm thick plate of Ti-5111 in the direction transverse to the weld. The weld showed significant increases in strength and ductility in the stir zone. The retreating side of the weld showed reduced strength and ductility below the base property. This result, however, was found to be limited to the microscale. The understanding gained from this research should lead to future process optimizations of FSW.