DISLOCATION PINNING IN HIGH TEMPERATURE DEFORMED Ni3(Al,Ti) SINGLE CRYSTALS CONTAIINING DISORDERED g PRECIPITATES
DISLOCATION PINNING IN HIGH TEMPERATURE DEFORMED Ni3（Al,Ti） SINGLE CRYSTALS CONTAINING DISORDERED γ PRECIPITATES

A transmission electron microscopy （TEM） investigation has been performed on the dislocation pinning in Lie-ordered Ni3（Al, Ti） containing disordered γ precipitates.The morphology of deformation induced dislocations in the γ base alloys containing fine dispersion of disordered γ was investigated by means of weak-beam electron microscopy. The superdislocations are strongly attracted to the disordered particles and dissociate on the （111） plane in the γ particles, while they dissociate on the （010） plane in the γ＇ matrix. The disordered γ precipitates play an important role as a pinning point during the cross-slip of superdislocations from （111） to （010） planes in the γ matrix and restrain the cross-slip of superdislocations. The interaction of superdislocations with disordered particles causes the formation of superkinks, jogs and closed loops.