Quantitative atomic force microscopy analysis of slip traces in Ni3Al yield stress anomaly

It is well known that Ni3Al intermetallic compounds of the L12 ordered structure exhibit positive temperature dependence of yield stress over a finite temperature range. In this work, we examined the slip markings produced by plastic deformation at the free surface of Ni3(Al,Hf) specimens deformed in situ under an atomic force microscope at room temperature. The results demonstrate that a high exhaustion in the mobile dislocation density does take place in the yield-stress anomaly of this alloy.