Author(s)

W. Chen, H. Chen, G. Schumacher & R.P. Wahi

Abstract

Deformation behaviour of polycrystalline (IN738LC) and single crystal (SCI6) superalloys has been investigated under creep-fatigue loading at 1223 K. Both the alloys show qualitatively a similar deformation behaviour: In the compres- sive part of the cycles a stable cyclic stress response was observed under all test conditions. The stress amplitude in compression increases with decreasing hold stress. The average creep rate during the hold periods as a function of number of load cycles shows a three stage behaviour: A rapid increase in the creep rate in the first stage. This increase in the creep rate is dependent on the levels of hold stresses. The second stage is characterised by a much slo

Keywords