C. G. Lee, Korea Institute of Machinery and Materials, Changwon, South Korea; S. J. Kim, Korea Institute of Materials Science, Changwon, Kyungnam, South Korea; S. Kim, Gyeongsang National University, Jinju, South Korea

Summary:

In the present study, corrosion and fatigue properties of friction stir welded 6061-T651 Al (4 mm thick) with varying welding parameters, including rotating and welding speeds, were examined. The resistance to corrosion was slightly improved, or at least did not decrease, for FSWed Al 6061-T651 alloy in 3.5% NaCl solution compared to the parent material. The effect of different welding conditions on the corrosion resistance was minimal. The resistance to stress corrosion cracking in 3.5% NaCl solution was considerably higher for the FSWed Al 6061-T651 compared to that of the PM counterpart. Propagation mechanisms of fatigue crack in the stir zone were changed following the values of stress intensity factor, DK. When DK was low, fatigue crack propagated along grain boundary. When DK was high, fatigue crack propagated through grain.