Kink-Band formation in Various Mille-Feuille Structured Mg- and Al-Based Materials

Mg-based LPSO phase is known to contribute to increase in both of strength and ductility of Mg alloys. As a deformation mode in it, kink-band formation is recently focused. A kink band is a deformation band formed by the explosive generation of dislocations in a localized region and their subsequent alignment along a direction normal to the slip plane. However, details of its formation criteria have not yet been clarified. According to the study on the LPSO phase, its unique crystal structure which is constructed by the alternative stacking of soft and hard layers, called mille-feuille structure, are supposed as plausible factors to govern the formation of deformation kink bands.<br/>To confirm these assumptions, we have examined the deformation behavior of several directionally solidified Mg-based and Al-based two-phase eutectic alloys with lamellar microstructure as a model material, such as Mg/Mg₁₇Al₁₂, Mg/Mg₂Yb and Al/Al₂Cu. Consequently, the formation of kink-bands was confirmed in all the alloys, as expected. The details of the deformation microstructure and accompanying deformation behavior will be discussed in the presentation.