PSI - Issue 17

Madhav Raturi et al. / Procedia Structural Integrity 17 (2019) 495–502 Madhav Raturi et al. / Structural Integrity Procedia 00 (2019) 000 – 000

499

5

Fig. 3. Macrographs of weld cross section of AA6061-AA2014 FSW joint obtained using TPZ pin profile at (a) 660 rpm , 36 mm/min; (b) 660 rpm, 63 mm/min; ( c) 900 rpm , 63 mm/min; (d)1200 rpm, 36 mm/min.

The variation of joint impact toughness for the dissimilar FSW welds between AA6061-T6 and AA2014-T6 for different process conditions with TIF and TPZ tool pins are also presented in Fig. 4(c). It may be noted from Fig. 4(c) that although higher UTS were obtained for the welded joints prepared with TIF tool pin, relatively higher impact toughness was recorded for joint prepared with TPZ tool pin. It was also observed that the toughness of the FSW joints was significantly higher than that of the base materials. This is possibly due to the fact that the notch for the impact test was created at the SZ which is characterized by the fine recrystallized grains as compared to the base materials.

200

200

160

160

120

120

40 W1 W2 W3 W4 Tensile Strength (MPa) 80

40 W5 W6 W7 W8 Tensile Strength (MPa) 80

2

4

6

8 10 12

2

4

6

8 10 12

Strain (%)

Strain (%)

(a)

(b)

100 125 150 175 200 225 250

0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25

UTS (MPa)

Impact Toughness (J)

UTS (MPa)

0 25 50 75

Impact Toughness (J)

W1 W2 W3 W4 W5 W6 W7 W8

Sample

(c)

Fig. 4. Representative stress-strain diagram of tensile test of joints prepared with (a) TIF; (b) TPZ tool pin; (c) comparison of tensile strength and impact energy.