25 An Experimental Study on Friction Stir …
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which need to be emphasized during the experiment [13]. It will affect the mechanical
properties of the weld specimen such as tensile strength and microstructure.
25.4 Results and Discussion
The welded specimen was inspected for their surface appearance and cross sections.
25.4.1 Surface Appearance of Welded Joints
The surface appearance of friction stir welded tee lap joint plates for different rotational and transverse speeds is represented in Fig. 25.5. The weld produced by the
lowest rotational and transverse speeds at 490 rpm/16 mm/s and 910 rpm/16 mm/s
showed a smooth welding surface without any lateral flash on the retreating and
advancing side. Meanwhile, the welding produced by the highest rotational and
transverse speeds showed a rough weld surface with literal flash at the retreating and
advancing side. It is due to the fact that the weld speed and heat produced by the
tool shoulder were insufficient. Hence, the welding parameters influence the surface
appearance of the welded joints.
25.4.2 Cross-Section Inspection of the Weld Zone
Based on Fig. 25.6, the cross section for the first experiment setting (490 rpm and
16 mm/min) showed sufficient penetration without any defect either on the advancing
or retreating sides. The same goes for the second experiment setting (910 rpm and
16 mm/min). However, for the last three settings, the cross sections showed a wormhole occurred on each weld zone either on the retreating or advancing side. Insufficient frictional heat supplied is the main cause of this condition due to high rotation
and increment of transverse speeds.
25.5 Conclusion
Based on this experiment, the lowest rotational and transverse speeds yielded the best
parameters for the tee lap joint configuration. The weld produced by the combination
of welding parameters of 490 rpm 16 mm/min and 910 rpm 16 mm/min were observed
to be in good shape of the joining with defect-free cross section.
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which need to be emphasized during the experiment [13]. It will affect the mechanical
properties of the weld specimen such as tensile strength and microstructure.
25.4 Results and Discussion
The welded specimen was inspected for their surface appearance and cross sections.
25.4.1 Surface Appearance of Welded Joints
The surface appearance of friction stir welded tee lap joint plates for different rotational and transverse speeds is represented in Fig. 25.5. The weld produced by the
lowest rotational and transverse speeds at 490 rpm/16 mm/s and 910 rpm/16 mm/s
showed a smooth welding surface without any lateral flash on the retreating and
advancing side. Meanwhile, the welding produced by the highest rotational and
transverse speeds showed a rough weld surface with literal flash at the retreating and
advancing side. It is due to the fact that the weld speed and heat produced by the
tool shoulder were insufficient. Hence, the welding parameters influence the surface
appearance of the welded joints.
25.4.2 Cross-Section Inspection of the Weld Zone
Based on Fig. 25.6, the cross section for the first experiment setting (490 rpm and
16 mm/min) showed sufficient penetration without any defect either on the advancing
or retreating sides. The same goes for the second experiment setting (910 rpm and
16 mm/min). However, for the last three settings, the cross sections showed a wormhole occurred on each weld zone either on the retreating or advancing side. Insufficient frictional heat supplied is the main cause of this condition due to high rotation
and increment of transverse speeds.
25.5 Conclusion
Based on this experiment, the lowest rotational and transverse speeds yielded the best
parameters for the tee lap joint configuration. The weld produced by the combination
of welding parameters of 490 rpm 16 mm/min and 910 rpm 16 mm/min were observed
to be in good shape of the joining with defect-free cross section.