Abstract

Abstract The critical resolved shear stress (CRSS) at 4.2 K for the (111)[01] slip system activation in Ni3(Si, Ti) single crystals with the Ll2 structure was measured by compression testing and the corresponding dislocation structures were investigated by means of TEM strong-and weak-beam methods. The CRSS showed strong orientation anisotropy and correspondingly a positive temperature dependence at this temperature. [01] screw superdislocations were dominant and sessile in all the observed crystal orientations. The superpartial dislocations combined with the APB tended to dissociate more widely onto the (010) cross-slip plane as the crystal orientation changed from [001] through [011] to [11]. It is suggested that the Kear-Wilsdorf locking is the most likely mechanism by means of which the strength anomaly observed at this temperature can be explained.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call