Influence of TMF Condition on Small Crack Propagation Behaviour in a Polycrystalline Ni-Base Superalloy

Abstract

In this work, the propagation behaviours of naturally initiated small crack in a polycrystalline Ni-base superalloy under the several kinds of TMF conditions were studied. The effect of phase angle between temperature and strain cycles in TMF loading on the propagation behaviour of small crack was discussed. The experimental results revealed that there was little influence of the phase angle on the small crack growth rates except the -90 degree condition when the crack growth rates of naturally initiated small crack are correlated with fatigue J-integral range.