TWI Industrial Member Report Summary 869/2007
By K A Beamish
Friction stir welding (FSW) is beginning to make a significant impact on the welding of aluminium alloys. The industrial pioneers in the development of FSW were companies with a strong research background which were able both to commission and interpret further research. The process is now sufficiently mature to be moving into market sectors where this is not necessarily the case. The wealth of data that exists in the public domain may not be accessible to these companies and, for reasons of commercial confidentiality, public domain material contains minimal practical guidelines. Many aspects of the process, particularly relating to tool design, were universally adopted because they were shown to give a good weld. It is only as the process is facing more challenging applications that there is the need to understand why, or indeed if, certain features are beneficial or detrimental to the quality of the weld produced.
In the present work, the effects of tool shoulder diameter, tool material, shoulder profile and alloy composition on the amount of heat generated during the FSW process have been investigated. Heat input is calculated from experimental torque measurements and combined with hardness traverses to provide a physical interpretation of the data. The results are compared with predictions from a simple analytical model and also with published experimental data. Recommendations are made regarding the identification of welding conditions for optimum heat generation.
- The influence of tool shoulder diameter on frictional heating in FSW.
- The influence of tool shoulder material on frictional heating in FSW.
- The influence of tool shoulder profile on frictional heating in FSW.
- How alloy composition affects heat generation using a single tool