Age hardening phenomena of rapidly quenched non-combustible Mg-Al-Si-Ca and Mg-Zn-Ca alloys

Abstract

Non-combustible Mg-Al-Si and Mg-Zn base alloys containing Ca were rapidly quenched via melt spinning. The melt-spun ribbons were aged, and then the effects of additional elements on age hardening behavior and microstructural change were investigated. Age hardening occurred after aging at 200 degreesC in the Mg-Al Si-Ca alloys mainly due to the formation of Al2Ca or Mg2Ca phases. whereas it occurred in the Mg-Zn-Ca alloys mostly due to the distribution of Mg6Ca2Zn3, and Mg,Ca. With the increase of Ca content, the hardness values of the aged ribbons were increased. In this study. Mg-6Zn-5Ca alloy showed the maximum peak hardness after aging at 200 degreesC for 1 hour. On the contrary, Mg-xZn-1.5Ca alloys couldn't show the pronounced peak hardness because of low Ca content.