*4.3. Bending Test*

Figures 12 and 13 are the post-bending test specimens for FSW and parent materials. The reddish-brown line appearing on specimens in Figure 12a,b indicates the center of the joint. The face and the root bending occurred towards the advancing side of the joint. This behaviour suggests that the joint was mechanically stronger compared to AA1050-H14, hence bending occurred on the advancing side. This behaviour is in agreement with the behaviour observed in the tensile analysis. The post-bending results showed the tested specimens without failure. This means that the welded materials bonded well during welding.

**Figure 12.** (**a**) Tested bending specimen (face), (**b**) Tested bending specimen (root).

**Figure 13.** Tested bending specimen (parent materials).

Figures 14 and 15 show bending stress and strain curves of the joint, together with parent materials. As it has been mentioned before that all the welded specimens bent on AA1050-H14, the flexural stresses for both face and root were within the range of that of AA1050-H14 (see Table 4). The average stress for face and root was 218.94 MPa and 259 MPa, respectively. These values suggest that the root side of the weld was stronger than that of the face. This could be caused by the fact that the lower side of the weld was exposed to the restricted downward movement due to bed backing plate. The flexural stress values were comparatively higher than the tensile values and this was due to higher temperatures involved during FSW.

**Figure 14.** Bending stress—strain curves (face).

**Figure 15.** Bending stress—strain curves (root).

**Table 4.** Bending test results.

