Effect of Si and Ca Addition on the Strengthening Behavior of Gravity-cast AM60 Magnesium Alloys

중력주조 AM60 마그네슘 합금의 강화 거동에 미치는 Si 및 Ca 첨가영향

  • Kim, Jae-Woo (Dept. of Metallurgical Eng., Yonsei University) ;
  • Kim, Do-Hyang (Dept. of Metallurgical Eng., Yonsei University) ;
  • Shin, Kwang-Seon (School of Materials Science and Engineering, Seoul National University & Jointly Appointed at the Center for Advanced Aerospace Materials)
  • 김재우 (연세대학교 금속공학과) ;
  • 김도향 (연세대학교 금속공학과) ;
  • 신광선 (서울대학교 재료공학부 및 항공재료연구센터)
  • Published : 1998.08.20

Abstract

Effects of Si and Ca additions on the mechanical properties of AM60 based Mg alloys have been investigated. Hardness of the AM60 based Mg alloys reached a maximum value after aging for approximately 33 hours but the amount of hardness increase was negligible. The poor age hardening response of the alloys was due to low Al content, which implies that Al content must be >6 wt.% to observe age hardening effect. The tensile and yield strength increased with increasing Al, Si, and Ca content but elongation decreased with increasing Al and Si content. The best mechanical properties obtained in AM 40-2.5Si-0.2Ca alloy after T4 heat treatment were as follows; tensile strength 193.4 MPa, yield strength 79.2 MPa, and elongation 11.2%. High temperature property obtained from creep test was also improved by introducing $Mg_2Si$ which has high hardness, high melting temperature and low thermal expansion coefficient.

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