Creep behaviour analysis of an oxide dispersion strengthened Ni3Al intermetallic material through the ñ model of dislocation-dispersoid interaction

Abstract

This research work presents an alternative description of the high temperature creep behaviour of an ordered oxide dispersion strengthened Ni₃Al intermetallic material to that recently presented by Klotz et al following an Arzt and Gohring model. An apparent stress exponent, n_ap, of 7.8 and an apparent activation energy, Q_ap, of 697 kJ/mole was obtained for this material. These values are approximately double than those for the non reinforced material. The dislocation-dispersoid interaction model, termed "ñ model", considers that this interaction merely raises the stress exponent associated to the non reinforced matrix by a value of ñ. Consequently, the apparent activation energy value is simultaneously raised. The ñ model predicts accurately the experimental data and presents advantages for analysing the creep behaviour of the dispersion strengthened materials.