**4. Effect of tool pin profile**

The fundamental role of the non-consumable rotating tool pin is to stir and transfer the plasticized metal behind it to a good joint. Pin profiles with flat faces (square and triangular) are associated with eccentricity. This eccentricity allows incompressible material to pass around the pin profile. **Figure 4** shows the effect of aluminum alloys of AA6061 on the FSW joints of tensile features. From this inquiry, it is discovered that the joints manufactured using the triangular pin tool profile have improved tensile characteristics for aluminum alloy. **Figure 5** shows the impact of the tool pin profile on AA6061 aluminum alloy FSW joints. From this study, it is discovered that the joints manufactured using Triangular pin tool profile improved impact strength for aluminum alloy. **Figure 6** shows the impact of tool pin profile on AA6061 aluminum alloy FSP area hardness. The FSP zone hardness is also maximum in the case of joints fabricated using **threaded** pin profile. **Figures 7–9** show the different zone of the microstructure of FSW joints of AA6061 aluminum alloys. The joint's FSP area made from threaded pin profile contains very fine equiaxed microstructure (**Figure 9**) compared to other joints.

**139**

**Figure 4.**

*(c) effect of axial force.*

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding*

*Effect of FSW parameters on tensile strength: (a) effect of rotational speed; (b) effect of welding speed; and* 

*DOI: http://dx.doi.org/10.5772/intechopen.89797*

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding DOI: http://dx.doi.org/10.5772/intechopen.89797*

#### **Figure 4.**

*Aluminium Alloys and Composites*

Impact strength (N/mm2

Impact strength (N/mm2

Impact strength (N/mm2

*Optimum parameters for the threaded pin profile.*

*Optimum parameters for the conical pin profile.*

*Optimum parameters for the triangular pin profile.*

**Table 4.**

**Table 5.**

**Table 6.**

**4. Effect of tool pin profile**

microstructure (**Figure 9**) compared to other joints.

using the diamond compound (1 mm particle size). Specimens are etched with the Keller's reagent, to reveal the macro and micro structures. SEM analysis is conducted using the Scanning Electron Microscope. SEM produces a range of signals exterior of sample specimens by utilizing the high energy focused electrons. Signals derived from SEM reveal information on the sample, including exterior morphology (texture), chemical composition, crystalline structure and orientation of the sample material.

Tensile strength (MPa) N3, S3, F3 162.84 163.23

Hardness N3, S3, F3 31 33

Tensile strength (MPa) N3, S3, F3 159.84 160.23

Hardness N3, S3, F3 28 30

Tensile strength (MPa) N3, S3, F3 218.34 215.82

Hardness N3, S3, F3 29 31

) N1, S2, F3 1.02 1.260

) N3, S3, F2 0.766 0.770

) N3, S3, F2 0.880 0.901

**Setting level Predicted Experimental**

**Setting level Predicted Experimental**

**Setting level Predicted Experimental**

The fundamental role of the non-consumable rotating tool pin is to stir and transfer the plasticized metal behind it to a good joint. Pin profiles with flat faces (square and triangular) are associated with eccentricity. This eccentricity allows incompressible material to pass around the pin profile. **Figure 4** shows the effect of aluminum alloys of AA6061 on the FSW joints of tensile features. From this inquiry, it is discovered that the joints manufactured using the triangular pin tool profile have improved tensile characteristics for aluminum alloy. **Figure 5** shows the impact of the tool pin profile on AA6061 aluminum alloy FSW joints. From this study, it is discovered that the joints manufactured using Triangular pin tool profile improved impact strength for aluminum alloy. **Figure 6** shows the impact of tool pin profile on AA6061 aluminum alloy FSP area hardness. The FSP zone hardness is also maximum in the case of joints fabricated using **threaded** pin profile. **Figures 7–9** show the different zone of the microstructure of FSW joints of AA6061 aluminum alloys. The joint's FSP area made from threaded pin profile contains very fine equiaxed

**138**

*Effect of FSW parameters on tensile strength: (a) effect of rotational speed; (b) effect of welding speed; and (c) effect of axial force.*

**Figure 5.** *Effect of FSW parameters on impact strength: (a) effect of rotational speed; (b) effect of welding speed; and (c) effect of axial force.*

**141**

**Figure 6.**

*of axial force.*

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding*

*Effect of FSW parameters on hardness: (a) effect of rotational speed; (b) effect of welding speed; and (c) effect* 

*DOI: http://dx.doi.org/10.5772/intechopen.89797*

*Experimental Investigations on AA 6061 Alloy Welded Joints by Friction Stir Welding DOI: http://dx.doi.org/10.5772/intechopen.89797*

**Figure 6.**

*Effect of FSW parameters on hardness: (a) effect of rotational speed; (b) effect of welding speed; and (c) effect of axial force.*

*Aluminium Alloys and Composites*

**140**

**Figure 5.**

*(c) effect of axial force.*

*Effect of FSW parameters on impact strength: (a) effect of rotational speed; (b) effect of welding speed; and* 

**Figure 7.** *Effect of conical pin profile on the microstructure of AA 6061: (a) FSP zone; (b) TMAZ; and (c) HAZ.*

**Figure 8.** *Effect of triangular pin profile on the microstructure of AA 6061: (a) FSP zone; (b) TMAZ; and (c) HAZ.*

**Figure 9.** *Effect of threaded pin profile on the microstructure of AA 6061: (a) FSP zone; (b) TMAZ; and (c) HAZ.*
