Stability of perfect dislocations in rare-earth intermetallic compounds: YCu, YAg and YZn

Abstract In this study, we evaluate the stability of prefect dislocations, interaction energy of kink pairs, cross-slip behavior of screw dislocations and the instability of pinned dislocations in ductile rare-earth intermetallic compounds: YCu, YAg and YZn. The results are compared to those seen for the common B2 type intermetallics, NiAl and Fe–25Al. The results indicate that the elastic anisotropy does not cause any instability of ordinary dislocations in YCu, YAg and YZn in contrast to NiAl and Fe–25Al. The cross-slip characteristics and the external driving force required for the instability of pinned dislocations differ considerably, resulting from their lower energy and the absence of negative line tension, from those seen for NiAl and Fe–25Al. The results also elucidate certain differences observed between the single crystalline deformation behavior of YCu, YAg and YZn.