Title of article :
Precipitate stability and recrystallisation in the weld nuggets of friction stir welded Al–Mg–Si and Al–Mg–Sc alloys
Author/Authors :
Sauvage، نويسنده , , X. and Dédé، نويسنده , , A. and Muٌoz، نويسنده , , A. Cabello and Huneau، نويسنده , , B.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
8
From page :
364
To page :
371
Abstract :
Two different precipitate hardening aluminium alloys processed by friction stir welding were investigated. The microstructure and the hardness of the as delivered materials were compared to that of the weld nugget. Transmission electron microscopy observations combined with three-dimensional atom probe analyses clearly show that β″ precipitates dissolved in the nugget of the Al–Mg–Si giving rise to some supersaturated solid solution. It is shown that the dramatic softening of the weld could be partly recovered by post-welding ageing treatments. In the Al–Mg–Sc alloy, Al3Sc precipitate size and density are unchanged in the nugget comparing to the base metal. These precipitates strongly reduce the boundary mobility of recrystallised grains, leading to a grain size in the nugget much smaller than in the Al–Mg–Si alloy. Both coherent and incoherent precipitates were detected. This feature may indicate that a combination of continuous and discontinuous recrystallisation occurred in the weld nugget.
Keywords :
Friction stir welding , Aluminium alloys , recrystallisation , Precipitates , Three-dimensional atom probe
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Serial Year :
2008
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Record number :
2157284
Link To Document :
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