Editorial

Abstract

Friction stir welding and processing has come a long way since the heady days of the pioneering work done at TWI in Cambridge some two decades ago. The FSWP 2010 conference held in Lille, France, during January, had the brief to cover in this context, the process, structure-property relationships, simulation and applications. Of the large number of papers presented at the conference, a selection which dealt with welding are included in this special issue of STWJ. All of these papers went through the usual independent refereeing and editorial procedures of the journal.It is interesting that nearly 30% of research papers on FSW published since 2008 are on dissimilar metal joining; this is a large increase when compared with the average over the last two decades. It is possible that with aluminium alloys at least, the joining of similar alloys is so well established that the research focus is now shifting to the more difficult joints between materials which may have vastly different physical properties. This topic was of course covered in a recent special issue of STWJ (Volume 15, Issue 4, described in Ref. 1), and it is not surprising that the Lille meeting contains some interesting contributions in this context.

Dissimilar friction stir welding of duplex stainless steel to low alloy structural steel

“…Welds between dissimilar metals and alloys have become an integral component within several engineering sectors due to the numerous economic and engineering benefits. 1 Examples include lightweight aluminium alloy to steel for use in the automotive 2 and aerospace sectors and dissimilar steels within the shipbuilding, power generation, and oil and gas industries due to different thermal and corrosive properties. 3 Such joints are typically produced using fusion welding techniques.…”

“…[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Extensive work has been carried out to demonstrate the advantages of FSW for a range of metals [24][25][26][27][28][29][30][31][32][33][34][35][36] and a growing amount of work for dissimilar alloys. 1,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Results from FSW of dissimilar materials highlighted the viability of such a process with the majority of reports concluding that high quality, defect free welds had been produced. Nevertheless, there were a few issues and considerations revealed: the level of material flow is closely linked to weld tool rotational speed, 8 high quality welds were produced when the material requiring the highest flow stress to induce ther...…”

“…With supporting evidence that FSW could be applied to dissimilar materials, 1, 8–23 some focus was shifted towards dissimilar steel joints. Research in FSW of dissimilar ferrous alloys is immature and continuing to develop, unlike more traditional fusion welding processes.…”