Friction stir welding - the state of the art

TWI Industrial Member Report Summary 678/1999

P L Threadgill

Background

Friction stir welding has emerged as a very important process for welding aluminium alloys, and is now making an impact in other materials. The process has attracted great interest for welding aluminium alloys, as it is a fully mechanical solid phase process, and can weld alloys such as many 2xxx and 7xxx alloys which cannot easily be welded by fusion processes.

The process has demonstrated low distortion, no need for consumables, all position capability and energy efficiency. The absence of fusion leads to no fume or spatter, and there is no arc to give ultraviolet or electromagnetic radiation.

Objectives

The objectives of the review are as follows:

• Provide a current overview of the current state of friction stir technology.
• Assemble a database of available mechanical properties.
• Identify areas where further research is required.