Al2MgC2 and AlFe3C formation in AZ91 Mg alloy melted in Fe-C crucibles

Magnesium alloys are commonly melted and held in steel or cast iron crucibles small but important amounts of Fe C can dissolve into Mg-rich melts. Here, carbide formation is studied during interface reactions between solid Fe-xC (x = 0–3.6 wt%) liquid Mg-9Al-0.7Zn-0.2Mn (wt.%, AZ91) at temperatures from 700 to 800 °C. Two ternary carbides, AlFe3C Al2MgC2, formed the reaction layers Fe-C AZ91, T2-Al2MgC2 additionally within AZ91 alloy due carbon pickup. grew as hexagonal plates that were twinned. A reproducible orientation relationship was measured ?-Mg, grain refinement magnesium by heterogeneous nucleation on explored.