A new model was developed in order to explain the mechanical properties of L12 Ni-based alloys; especially with regard to their anomalous increase in yield-stress with increasing temperature. The dislocation movements were assumed to be controlled by a series of double cross-slip mechanisms, between octahedral and cube planes, which led to the formation and destruction of incomplete Kear-Wilsdorf locks. The model was 2-dimensional, and the splitting of super-partials into Shockley partials was not taken into account. The forces which acted on the leading and trailing super-partials of incomplete Kear-Wilsdorf locks were computed. Fairly good values of the flow stress were predicted at low and high temperatures by assuming that the ratio of the interphase boundary energies in cube and octahedral planes was 0.9, and by assuming that the distance of cross-slip onto the cube plane increased with increasing temperature.

D.Caillard, V.Paidar: Acta Materialia, 1996, 44[7], 2759-71