from FSW can be broadly categorised into 3 distinct groups, metallurgical, environmental, and energy. A full list of the advantages can be below in table 2.1.4.1 which was taken from their research paper: Table 2.1.4.1 – Advantages of FSW [Mishra and Ma, 2005] Metallurgical advantages Environmental Advantages Energy Advantages Solid state joining process No Shielding gas required Improved materials use (i.e. joining different thickness) allows reduction in weight Low distortion of work piece No surface cleaning required Only 2.5% of energy needed for a weld Good dimensional stability and repeatability Eliminate grinding waste Decreased fuel consumption in light weight aircraft, automotive and ship applications No loss of alloying elements Eliminate solvents required for degreasing metallurgical properties in joint area Consumable materials saving, such as rugs, wire or any other gases Fine microstructure Can be performed water Replace multiple joined by fastener Absence of cracking 2.1.7 – Advantages of Stationary Shoulder Corner FSW The most critical advantage of the process is that now angled plates can be welded, but also produce rounded effects, or other shapes if necessary. As SSCFSWelding involves the use of a stationary shoulder there is a reduced heat input compared to that of fixed shoulder, which generally results in improved weld microstructure and properties. It now is easier to add ribs and straighteners to existing components, but also eliminate any weak corners from other weld types. Other advantages are listed below: Reduced use of energy compared to that of MIG, TIG, and welding types Reduced material wastage Weld quality is far more uniform than other welding types No fume extraction is required, giving a better working environment Allows for full FSW construction Can eliminate need for sealants on aerospace stringers Improved corrosion resistance More light weight joints 2.1.8 - Limitations to FSW There are several drawbacks to the both the FSWelding process and the SSCFSWelding process. In both cases the workpiece has to be firmly clamped and a there is a key hole from where the FSW tool has exited the weld. For SSCFSW it requires to two runs for either side of the t-weld,
microstructural zones including the HAZ, TMAZ, and DRX, but also show and contrast blade and regions. Once again the weld shows a great deal of similarity to the SSCFSW weld, including blade and non-blade regions. Figure 4.2.1.A – Overall macrograph of the second SSCFSW for AA6082-T6, with marked which have been analysed at higher magnification Figure 4.2.1.B – Area 1 in figure 4.2.2.A, showing the HAZ) Figure 4.2.1.C – Area 2 in figure 4.2.2.A, showing the transition from the HAZ (left) to TMAZ to DRX (right) for the advancing side of the weld. Figure 4.2.1.D – Area 3 in figure 4.2.2.A, showing the DRX and the transition from the (left) to the non-blade region (right) Figure 4.2.1.E – Area 4 in figure 4.2.2.A, showing the transition from the DRX (left) to TMAZ (centre) to HAZ (right) for the retreating side of the weld Figure 4.2.1.F – Area 5 in figure 4.2.2.A, showing the TMAZ (left) transitioning to the HAZ Figure 4.2.1.G – Area 6 in figure 4.2.2.A, showing the non-blade region at the very base of the weld Figure 4.2.1.H – Area 7 in figure 4.2.2.A, showing the blade region (purple shading) and the region (light shading) Figure 4.2.1.I – Area 8 in figure 4.2.2.A, showing the blade region (purple shading) and the non-blade region (light shading) Figure 4.2.1.J – Area 9 in figure 4.2.2.A showing the blade region (purple shading) and the non-blade region (light shading)
Figure 4.4.4.G – A rotated IPF colouring map indicated in Figure 4.4.4.B and the resulting ODF sections at ф2 = 0° and ф2 = 45° (where the y-axis is ф (0-90°), and the x-axis is ф1 (0-360°)) in steps across the entire AA6082-T6 SSCFSW DRX for the wire filler region.
Figure 4.4.5.D – A rotated IPF colouring map indicated in Figure 4.4.5.B and the resulting ODF sections at ф2 = 0° and ф2 = 45° (where the y-axis is ф (0-90°), and the x-axis is ф1 (0-360°)) in steps across the entire AA6082-T6 SSCFSW DRX for the base region.
Figure 6.6.1.D – A rotated IPF colouring map indicated in Figure 6.6.1.B and the resulting ODF sections at ф2 = 0° and ф2 = 45° (where the y-axis is ф (0-90°), and the x-axis is ф1 (0-360°)) in steps across the entire AA7075-AA2014 SSCFSW DRX.
Figure 7.6.5.C – EBSD IPF colouring map after correction with respect to ND for an AdstirTM weld (see Figure 7.6.4) and below the map (111) pole figures in 500-600 m steps across the whole AA7075-AA2024 DRX. Figure 7.6.5.D – EBSD IPF colouring map correction with respect to ND for a fillet weld (see Figure 7.6.4) and below the map (111) pole figures in m steps across the whole AA7075-AA2014 DRX. Figure 7.6.5.E – Texture components map for an AdstirTM weld of AA7075-AA2024 after rotation correction with (red), (yellow), and C (blue). Figure 7.6.5.F – Texture components map for a fillet weld of AA7075-AA2014 after rotation correction with (red), (yellow), and C (blue).
Figure 2 – Second Weld 7075-T6/2014-T4 for traverse speed 125 mm/min High energy input - 50mm/min traverse speed Figure 3 – Weld 7075-T6/2014-T4 for traverse speed 50 mm/min Figure 4 – Second Weld 7075-T6/2014-T4 for traverse speed 50 mm/min 6082-T6 Welds Traverse Speeds 100-300mm/min Figure 5 – First Weld 6082-T6 for traverse speed 100 mm/min Figure 6 – First Weld 6082-T6 for traverse speed 150 mm/min Figure 7– First Weld 6082-T6 for traverse speed 200 mm/min Figure 8 – Weld 6082-T6 for traverse speed 250 mm/min Figure 9 – First Weld 6082-T6 for traverse speed 300 mm/min 5083-0 Figure 10 – Weld 5083-T6 for traverse speed 125 mm/min Appendix B – EDAX plots for copper tracer samples Site 1
Figure 1 - Point 1 Figure 2 - Point 2 Figure 3 - Point 3 Figure 4 - Point 4 Figure 5 - 5 Figure 6 - Point 6 Figure 7 - 7 Figure 8 - Point 8 Figure 9 - Point 9 Site 2 Figure 10 – Site 2 Point 1 Figure 11– Site 2 Point 2 Figure 12 – Site 2 Point 3 Figure 13 – Site 2 Point 4
Figure 14 – Site 2 Point 5 Figure 15 – Site 2 Point 6 Figure 16 – Site 2 Point 7 Figure 17 – Site 2 8 Site 3 Figure 18 – Site 3 Point 1 Figure 19 – Site 3 2 Figure 20 – Site 3 Point 3 Figure 21 – Site 3 Point 4 Figure 22 – Site 3 Point 5 Figure 23 – Site 3 Point 6 Figure 24 – Site 3 Point 7 References Mohamed Mohamed Zaky, Ahmed, The Development of Thick Section Welds and Ultra-Fine Grain Aluminium Using Friction Stir Welding and Processing, 2009