Preparation and solidification features of AS21 magnesium alloy

AS21 magnesium alloy was developed for high temperature applications that r equire adequate creep resistance. The present study aimed at obtaining info rmation regarding preparation procedure and phase constituents that are pre cipitated during solidification of AS21 alloy and can affect the performanc e of this alloy in service conditions. Magnesium alloys are usually alloyed with manganese to remove iron. Hence, the understanding the factors which affect the mutual solubility of Mn and Fe in molten magnesium is very impor tant for establishing the efficient alloying procedure with Mn, Al and Si i n AS21 alloy. Silicon is added to Mg-Al alloys in order to enhance the cree p resistance. It was believed that only Mg2Si particles are formed through the solidification process of AS21 alloy. However, it is evident from the r esults of present investigation that additional phases are present in the A S21 ingots. The sequence of phase transformations occurring through the sol idification process were discussed and the factors affecting the microstruc ture features were disclosed. (C) 2001 Elsevier Science B.V. All rights res erved.