부산대학교 도서관

Twin–twin interaction plays an important role in tailoring the mechanical properties of magnesium (Mg) alloys. In thisstudy, we studied the effect of different types of twin–twin interactions (Type I, Type II-a and Type II-b) on the subsequentmicrostructure evolution and mechanical properties through quasi-in-situ electron backscatter diffraction, molecular dynamicssimulation and mechanical property test. The results showed that de-twinning and nucleation of secondary twin from the twinboundary dominates plastic deformation during Type II twin–twin interactions, while twin growth dominates plastic deformationduring Type I twin–twin interactions. Type II twin–twin interactions can improve both strength and plasticity comparedto the Type I twin–twin interactions. In addition, the twin–twin interactions form a stress concentration near the interactionsite, but the magnitude and release method of the stress are different for Type II and Type I. The internal stress induced byType II is released through de-twinning or formation of new twins from twin boundary, while the internal stress induced byType I is released through merge and growth of initial twin. Such a microstructure evolution mechanism of different typesof twin–twin interactions provides a new vision of twining/de-twinning behavior and tailoring mechanical properties.