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Friction stir welding (FSW) experiments were conducted on magnesium alloys, wrought AZ31 (Mg, 3%Al, 1%Zn) and cast AZ91 (Mg, 9%Al, 0.6%Zn), to investigate the effect of process conditions on microstructure and hardness. Welding was performed at rotational speeds of 200 or 300 rpm and traverse speeds of 150-450 mm/min. The macrostructure and microstructure of welded joints were observed by optical microscopy and SEM. Microhardness profiles were measured in a Vickers hardness testing machine. Microstructure evolution and hardness in the weld nugget and thermomechanically affected zone were compared for the two alloys.

7th International Symposium, 20-22 May 2008, Poster Session, Paper 13