Friction Stir Spot Welding: A Review on Joint Macro- and Microstructure, Property, and Process Modelling

Abstract

Friction stir spot welding (FSSW) is a very useful variant of the conventional friction stir welding (FSW), which shows great potential to be a replacement of single-point joining processes like resistance spot welding and riveting. There have been many reports and some industrial applications about FSSW. Based on the open literatures, the process features and variants, macro- and microstructural characteristics, and mechanical properties of the resultant joints and numerical simulations of the FSSW process were summarized. In addition, some applications of FSSW in aerospace, aviation, and automobile industries were also reviewed. Finally, the current problems and issues that existed in FSSW were indicated.

The Effect of RFSSW Parameters on the Load Bearing Capacity of Aluminum 7075-T6 Sheet Metal Joints

“…After substituting the determined values of the b o , b k , b kk , b kj coefficients in to equation (1), the following regression equation was achieved: To determine how adequate the regression equation is, a Fisher-Snedecor test was used. During first stage of the analysis, the adequateness variance was determined: (14) where: y ̅ i -average value of measurement results in the i th experiment, y ̅ i -the value calculated from the regression equation for initial and result factors of the i th experiment, k -the number of regression equation expressions (without a free expression) after rejecting insignificant expressions, r -number of repetitions, N -number of experiments Next, the value of the F test coefficient were determined: (15) It was compared with the critical value from the Fisher-Snedecor distribution F kr = F (a, f1, f2) = F (0.05, 3,18) = 3.1599. Due to the value of the test coefficient being smaller than the critical value F < F kr (2.5095 < 3.1599), the resulting regression equation (13) was accepted as adequate with a significance level of α = 0,05.…”

“…Spot welding causes a decline in riveting and gluing light alloys because of its multiple advantages [1,8,[18][19][20][21]:…”

Friction Stir Spot Welding-Brazing of Al and Hot-Dip Aluminized Ti Alloy with Zn Interlayer

“…In a typical FSSW, a rotating cylindrical pin tool is plunged into the workpiece to be welded. Frictional heat is generated in the plunging and stirring stages, and thus the materials adjacent to the tool are heated, softened, and mixed in the stirring stage where a solid-state joint will be formed [18]. Up to now, many reports on FSSW of similar or dissimilar metals mainly focus on the process, microstructural characteristics, and numerical simulations to A molten bath consisting of pure Al (99.9 wt.%) was used for the hot-dip aluminizing of the Ti6Al4V alloy.…”

“…Because of the increase of the joining area, the maximum fracture load of such joint is 110% higher than that of the traditional FSSW joint under the same welding parameters. The fracture load of these joints depends on the joining width, including the width of solid-state bonding region in stir zone and brazing region out of stir zone.optimize the mechanical properties of the joint [17][18][19][20][21]. Unavoidably, the traditional FSSW would leave a keyhole that reduces its bonding area [22].…”

“…optimize the mechanical properties of the joint [17][18][19][20][21]. Unavoidably, the traditional FSSW would leave a keyhole that reduces its bonding area [22].…”