A New Insight in the Plasticity of Ni3Al Intermetallic Compounds Using AFM Observations

Abstract

The positive temperature dependence of flow stress in Ni3Al is examined through fine slip trace analysis performed by atomic force microscopy. Slip traces, which result from dislocation movements, constitute outstanding markers for investigating the elementary dislocation mechanisms that control plasticity. The experiments were performed on two Ni3Al-base alloys, with Ta or Hf as additional elements. The results give evidence that the anomaly domain is accompanied by a drastic exhaustion of mobile dislocations and very short cross-slip distances on the cube cross-slip plane.