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