AA2024-T3 1 Aluminum alloys 1 Dissimilar materials 1 Friction 1 Friction stir 1 Friction stir spot welding 1 Friction stir welding 1 Lap shear Machine learning 1 Optimisations 1 Polynomial regression 1 Refill friction stir spot welding 1 Rotational speed 1 Shear flow 1 Shear force 1 Spot welded 1 Spot welding 1 machine learning 1 optimization 1 polynomial regression 1 refill friction stir spot welding 1