Effect of second phase particles on the microstructure and texture of rare earth elements containing magnesium matrix surface-composite produced by friction stir processing

The present research clarifies the texture and microstructure evolution of a rare earth (RE) containing magnesium composite reinforced by SiC particles (Mg-RE/SiC) during friction stir processing. Rotating tool induced mechanical stirring and frictional heat lead to occurrence of dynamic recrystallization (DRX) and development of the strong basal texture component. The presence of second phase particles in the matrix could stimulate the occurrence of continuous dynamic recrystallization (CDRX) and particle stimulated nucleation (PSN) and postpone discontinuous dynamic recrystallization (DDRX). The presentation of crystallographic orientations in an appropriate reference frame indicated formation of a new rare earth texture (RE-texture) component, near the <11-24>//shear plane normal (SPN) and <20-21>-<11-21>//shear direction (SD) orientations. This texture component was developed through simultaneous activity of basal and non-basal slip systems during dynamic recrystallization.