Preface to the Viewpoint Set on Friction Stir Processing


Inventions can be generally classified in two categories: those looking for solutions and those providing solutions. Friction stir welding (FSW) was invented at a time when the joining community was looking for an effective solution for welding of high strength aluminum alloys [1]. Quite naturally, the aerospace companies took the lead in evaluating and adopting this technology. In the first 10 years after the invention of FSW, technological development far exceeded efforts in fundamental research. There might even have been an initial perception that it is a 'very easy' process! However, the reality is quite different. The friction stir process is fully coupled thermomechanically and the material flow is quite complex. Understanding of material flow and microstructural evolution has become even more important for friction stir processing [2], which broadens the applicability of the friction stir process as a general metallurgical processing tool for microstructural modification. The development of friction stir processing as a general microstructural modification tool started with the initial work of Mishra, Mahoney and co-workers and has progressed to encompass many variants. The scientific and technical activities in the field of FSW and processing have reached a critical juncture in terms of number of researchers and number of publications/year (see Ref. [3] for a comprehensive compilation of information by various authors). The underlying scientific issues have emerged and recent publications have started bringing clarity to various aspects of the friction stir process. The intent of this Viewpoint Set is to put together a set of articles covering various friction stir scientific issues written by some of the leading researchers in this area. To stimulate discussion and to ensure that some of the key issues are covered, the authors were provided with Figure 1, which summarizes important subsections of friction stir scientific issues, and the set of questions that follow.


Materials Science and Engineering

Keywords and Phrases

Friction Stir Welding; Material Flow; Aluminum alloys

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2008 Elsevier, All rights reserved.

Publication Date

01 Mar 2008