This paper presents a new welding quality evaluation approach depending on the analysis

by the fuzzy logic and controlling the process capability of the friction stir welding of

pipes (FSWoP). This technique has been applied in an experimental work developed by

alternating the FSW of pipes process major parameters: rotation speed, pipe wall thickness

and travel speed. variable samples were friction stir welded of pipes using from 485 to 1800

rpm, 4–10 mm/min and 2–4 mm for the rotation speed, the travel speed, and the pipe wall

thickness respectively. DMAIC methodology (Defining, Measuring, Analyzing, Improving,

Control) has been used as an approach to analyze the FSW of pipes, it depends on the

attachment potency and technical commonplace demand of the FSW of pipes process.

The analysis controlled the Al 6061 friction stir welded joints’ tensile strength. To obtain

the best tensile strength, the study determined the optimum values for the parameters from

the corresponding range.