The yield stress of Ni 3(Al, W)

Abstract

An investigation of the mechanical behavior in compression of oriented Ni 3(Al, W) single crystals was undertaken. The yield stress at a plastic strain of 5 × 10 −5 was obtained over the temperature range 77°K to 875°K for samples prestrained at 77°K. Dislocation rearrangements in specimens prestrained at 77°K and then stressed at 298°K demonstrate that the 6 × 10 −5 offset yield stress is controlled by the easy movement of edge dislocations. This results in an exhaustion hardening phenomenon in the premacroyield region due to the loss of mobile edge dislocations. A measurement of the macroscopic yield stress reveals a temperature dependence between 77°K and 4°K typical for pure f.c.c. metals.