Fragmentation of Mg24Y5 intermetallic particles in an Mg-Zn-Y alloy during the equal channel angular pressing

Transmission Kikuchi diffraction (TKD) and transmission electron microscopy (TEM) have been used to investigate the fragmentation of Mg24Y5 intermetallic particles in an Mg-Zn-Y alloy during the equal channel angular pressing (ECAP). During the ECAP process, micro-cracks formed in large Mg24Y5 particles and dynamic recrystallised Mg grains were observed inside the crack. The dynamic recrystallisation of the Mg24Y5 also occurred and the particle size has been reduced. The recrystallised Mg24Y5 particles assume either an irregular or necking shape contributing to the dispersion of the small particles. The fragmentation of the Mg24Y5 particles also reduced the grain size of the surrounding magnesium grains. The refinement of the intermetallic particles is expected to improve the strength and ductility of the alloys.