Mathematical Modelling of a Friction Stir Welding Process to Predict the Joint Strength of Two Dissimilar Aluminium Alloys Using Experimental Data and Genetic Programming

Table 2

Important input factors and their levels.

Process parameters	Symbol	Unit	Level 1	Level 2	Level 3
Tilt angle		(°)	3	4	- -
Axial load		(KN)	2	2.5	3
Tool rotational speed		(rpm)	600	900	1200
Welding speed		(mm/sec)	70	90	115
Thickness of plate		(mm)	3	4	5