Work softening and microstructural instability of predeformed molybdenum single crystals

Abstract Molybdenum single crystals predeformed at or below room temperature exhibited during tensile loading at 493 K a sharp yield drop, serrated yielding and localized slip. It is shown that these phenomena are correlated with the instability of the dislocation structure of the cold worked state resulting in the formation of obstacle-free slip channels. The results are discussed in connection with dislocation channelling and plastic strain concentration in variously strengthened metals under unidirectional and cyclic loading.