Evaluation of Joint Properties of Friction Stir Welded AZ31B Mg Alloy

Noh, Joong-Suk; Kim, Heung-Ju; Chang, Woong-Seong; Bang, Kook-Soo

Journal of KWJS 2004;22(3):56-61.
Published online September 15, 2004.

[연구논문] FSW를 이용한 AZ31B Mg 합금의 접합성 평가

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Evaluation of Joint Properties of Friction Stir Welded AZ31B Mg Alloy

Joong-Suk Noh, Heung-Ju Kim, Woong-Seong Chang, Kook-Soo Bang

Abstract

Friction' stir weldability of AZ31 B Mg alloy was studied using microstructural observation and mechanical tests. Defect free joints was obtained under the condition of 2000rpm-100mm/min. In TMAZ, a lot of twin deformation were observed due to the mechanical effect of the FSW tool and thus relatively high hardness was obtained. In SZ, the twin deformation was disappeared by recovery and the hardness decreased because the grain structure was coarsened by dynamic recrystallization and grain growth. The AI-Mn precipitates were observed throughout the joint regions. On the other hand, P-MgI7AI12 intermetallic compounds were not observed in either of the zone. The joint efficiency was about 80% and the impact value of the joint was almost equal to that of base metal.