m.a safarkhanian - iran university of science &tech
m goodarzi
s.m.a boutorabi

in this study the microstructure of stir zone in the joints has been investigated . Two rotational speeds 450and 900 rpm used and it was found that the particles are broken up during friction stir welding and the severity of breaking up of the particles in the stir zone increases with increasing rotational speed since the dynamic recrystallization occurs simultaeously with breaking up of particles during friction stir welding the most of particles locate at grain boundaries in the in the stir zone of as -welded joints the breaking up and locating of these particles in grain boundaries affect on mechanical properties and the stabilizing of grains during post weld heat treatment .

friction stir welding ,aluminum alloys ,particles