Microstructural Evolution during Friction Stir Processing of Magnesium Alloy Castings
Friction stir processing (FSP) of cast AM60 magnesium alloy has been studied using the breaking pin method, freezing the microstructure during the process. Strong evidence is seen that partial melting plays a key role in removing the β-Mg17Al12, whereas the manganese rich intermetallics persist during FSP. This is consistent with temperature predictions made using a process model adapted to FSP of AM60 castings that show the eutectic melting point is exceeded.
Jian-Feng Nie and Allan Morton
J. D. Robson et al., "Microstructural Evolution during Friction Stir Processing of Magnesium Alloy Castings", Materials Science Forum, Vols. 654-656, pp. 751-754, 2010