Table 9 The mechanical properties of samples fabricated with the optimal welding values.

From: A multi-objective optimization using response surface model coupled with particle swarm algorithm on FSW process parameters

Parameter/objective

Threaded cylindrical pin

Conical pin

Pin diameter (mm)

4.49

4.50

Shoulder diameter (mm)

16.62

14.03

Feed rate (mm/min)

41.23

67.66

Rotational speed (rpm)

814.72

867.73

Tool tilt angle (°)

3.41

2.54

Predicted yield stress (MPa)

27.15

32.15

Experimental yield stress (MPa)

31.04

27.60

Yield stress prediction error (%)

14.34

14.14

Predicted impact toughness (MJ/m2)

0.47

0.37

Experimental impact toughness (MJ/m2)

0.44

0.36

Impact toughness prediction error (%)

5.64

1.36

Predicted failure strain

15.91

17.51

Experimental failure strain

16.81

16.49

Failure strain prediction error (%)

5.69

5.81

Predicted HAZ hardness on advancing side (HRB)

22.98

16.48

Experimental HAZ hardness on advancing side (HRB)

24.56

14.90

HAZ hardness on advancing side prediction error (%)

6.88

9.58

Predicted HAZ hardness on retreating side (HRB)

21.24

15.38

Experimental HAZ hardness on retreating side (HRB)

22.34

14.20

HAZ hardness on retreating side prediction error (%)

5.17

7.67