Mechanical Properties Optimization of Friction Stir Welded Lap Joints in Aluminium Alloy

Table 10

Yield strength, ultimate strength, and elongation experimental responses performed along the steepest ascent direction (summarized data for nugget and HAZ).

rpm	s/mm	Avg. YS	Avg. US	Avg. El
Nugget
1250	0.241	399.25	511.8	28.75
1150	0.213	395.8	507.9	26.36
1050	0.184	339.33	453	25.25
950	0.155	368.67	475.6	25.23
HAZ
1250	0.241	370	482.3	19.8
1150	0.213	368	474.5	20.17
1050	0.184	386	491	21.4
950	0.155	405.7	506.25	21.45