Investigation of the microstructure and the influence of iron on the formation of Al8Mn5 particles in twin roll cast AZ31 magnesium alloy

The influence of iron on the formation of Al8Mn5 particles during twin roll casting of AZ31 magnesium alloy and the alloy microstructure has been investigated. Flower-shaped Al8Mn5 particles with sizes of 50-500 nm were observed at the grain centres and the grain boundaries. Additionally, Fe-particles with faceted morphologies and dimensions of less than 100 nm were observed at the centres of the Al8Mn5 particles, suggesting that the α-Fe particles acted as effective nucleation sites for the Al8Mn5 particles.