Effect of ternary iron addition on the creep behaviour of NiAl

Constant load creep tests have been carried out on polycrystalline NiAl in the temperature range 750–900 °C and at stresses from 35 to 75 MPa. It was found that the creep rate of NiAl is controlled by dislocation climb, which gives rise to a well defined substructure; the addition of iron, which decreases the diffusion coefficient of NiAl, decreases the steady state creep rate of NiAl appreciably. Dislocations with a 〈100〉 Burgers vectors operate in both regimes, predominantly on {001} in the primary region and also on {011} in the steady state region.