TWI Industrial Member Report Summary 761/2003
P L Threadgill
Friction stir welding is now becoming well established for aluminium alloys, and there is a significant volume of research and development in progress to allow materials with higher melting points, eg copper based alloys, titanium based alloys, steels and nickel based alloys to be welded by this process. One of the most challenging tasks in this work has been the identification of a suitable tool material.
Work to date in selecting a tool material has often taken an ad-hoc approach, and although this has identified useful materials, there is little quantitative understanding of the criteria which must be applied to allow better materials to be selected.
This report examines the role of the tools, and the performance of several materials from which tools can be made, in order to establish more critical materials selection criteria.
The objectives of this work are as follows:
- Review existing knowledge on materials with potential for use as friction stir welding tools.
- Review the performance of these materials, where known.
- Determine criteria for selection of tool materials.