Effect of prior cyclic oxidation on the creep behavior of directionally solidified (DS) CM-247LC alloy

The effect of cyclic oxidation exposure on the tensile creep properties of a directionally solidified Ni-base superalloy (CM-247LC) has been evaluated at a stress–temperature combination of 220 MPa/980 °C. Cyclic oxidation of creep specimens has been carried out 1100 °C in air up to 750 h. The creep properties (creep rate, creep strain and creep life) were found to be adversely affected by the oxidation exposure. The extent of degradation of the properties increased with increase in the duration of oxidation. Such deterioration of creep properties of the alloy has been correlated with the surface damage and general microstructural degradation that occur in the alloy during oxidation exposure.