What can be learnt on the yield stress anomaly of Ni3Al using AFM observations

J. Michel (1) , C. Coupeau (1) , Y. Nahas (1) , M. Drouet (1) , J. Bonneville (1)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]

We examined by in situ scanning probe microscopy the slip traces at the free surface of Ni3(Al,Ta) single crystals deformed in ultra high vacuum environment at various temperatures. It is evidenced that the mean free path of superdislocations in the primary octahedral planes strongly decreases with increasing temperatures. This is quantified by the decrease in the number of dislocations along slip traces corresponding to the primary (111) slip planes. Correlatively the number of cross-slip events increases with increasing temperature, together with a drastic increase of the distance travelled by the dislocations on the cube cross-slip plane. The experimental results are discussed in the frame of previous theoretical models that have been proposed to predict the yield stress anomaly of L12 intermetallic compounds.

Mots clés: B. Mechanical properties; B. Plastic deformation mechanisms; B. Slip system; D. Dislocation geometry and arrangement; F. Atomic force microscopy; G. Aeroeengine components

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]

J. Michel, C. Coupeau, Y. Nahas, M. Drouet, J. Bonneville. What can be learnt on the yield stress anomaly of Ni3Al using AFM observations. Intermetallics, 2014, 50, pp.86-93. ⟨10.1016/j.intermet.2014.02.013⟩. ⟨hal-03678894⟩