Evaluation of FSW Weldability of Wrought and Casting Mg Alloys

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

Journal of KWJS 2004;22(5):53-57.
Published online November 12, 2004.

[연구논문] 전신 및 주조된 Mg 합금의 FSW 접합성 평가

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Evaluation of FSW Weldability of Wrought and Casting Mg Alloys

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

Abstract

Friction stir weldability of AZ31B-H24, AZ61A-F and AZ91C-F Mg alloys were studied using microstructural observation and mechanical tests. The microstructure of stir zone (SZ) was coarse in AZ31B-H24 alloy whereas it was very fine both in AZ61A-F and AZ91C-F alloys. The hardness of SZ was remarkably increased by very fine recrystallized grains both in AZ61A-F and AZ91C-F alloys. On the other hand, the hardness of SZ was decreased in AZ31B-H24 due to the coarse microstructure. In SZ, AZ91C-F alloy showed very high hardness values because of dispersion hardening of Mg_17Al_12(β phase) and Al solid solution hardening. Because of more Mg_17Al_12(β phase) intermetallic compounds, Mg alloy with high Al content showed poor mechanical properties.