The Effect of Ca Addition on the Grain Refinement and Mechanical Properties in Mg-Zn Alloy

Mg-Zn 합금의 결정립미세화와 기계적 성질에 미치는 Ca 첨가의 영향

  • Eom, Jeong-Pil (Research Center for Aircraft Parts Technology, Division of Materials Enineering, Gyeongsang National Univ.) ;
  • Lim, Su-Gun (Research Center for Aircraft Parts Technology, Division of Materials Enineering, Gyeongsang National Univ.) ;
  • Hur, Bo-Young (Research Center for Aircraft Parts Technology, Division of Materials Enineering, Gyeongsang National Univ.)
  • 엄정필 (경상대학교 재료공학부, 항공기부품기술연구센터) ;
  • 임수근 (경상대학교 재료공학부, 항공기부품기술연구센터) ;
  • 허보영 (경상대학교 재료공학부, 항공기부품기술연구센터)
  • Published : 2000.12.20

Abstract

The main interdendritic phase which was formed during early solidification of the ternary Mg-Zn-Ca alloys is the $Ca_2Mg_6Zn_3$ phase. The microstructure of $Mg-6wt%Zn-0.1{\sim}0.3wt%Ca$ alloys consisted of MgZn precipitates and $Ca_2Mg_6Zn_3$ phase formed around the grain boundaries. In the alloys with the highest level of Ca($Mg-6wt%Zn-0.5{\sim}0.7wt%aCa$ alloys), the microstructure revealed wholly $Ca_2Mg_6Zn_3$ phase formed around the grain boundaries. The grain size of Mg-6wt%Zn-Ca alloys decreased significantly with increase in Ca content and, at 0.5wt% Ca or more, grain size becomes constant at about 60 ${\mu}m$. The tensile properties of the as-cast Mg-6wt%Zn-Ca magnesium alloys were improved due to grain refinement by addition of Ca.

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