Friction-Stir Welding of High-Softening-Temperature Materials Using Cobalt-Based Alloy Tool
The authors have developed a new friction-stir welding (FSW) tool that enables to weld high-softening-temperature materials (HSTMs), such as steels, titanium and zirconium alloys. The new tool is made of a Co-based heat-resistant alloy strengthened by precipitating intermetallics, Co3(Al,W), with a L12 structure at high temperatures. The Co-based alloy tool exhibits yield strengths higher than 500 MPa at 1000 deg C, so it might have a great potential as a tool material for FSW of HSTMs. In this study, the feasibility of using the Co-based alloy tool with various HSTMs was examined. Changes in the tool shape during FSW and the weld appearances produced with the Co-based alloy tool will be briefly shown.
T. Chandra, M. Ionescu and D. Mantovani
S. H. C. Park et al., "Friction-Stir Welding of High-Softening-Temperature Materials Using Cobalt-Based Alloy Tool", Materials Science Forum, Vols. 706-709, pp. 996-1001, 2012