Creep deformation behaviour of Rhenium free Ni-based single crystal superalloys LSC-15

In this paper, creep deformation behavior of Ni-based single crystal superalloys LSC-15 were studied. LSC-15 does not include Rhenium and has been developed by IHI Corporation Japan. Creep tests were performed at 1000 and 1050 ∘C under several stress levels. The creep deformation behaviour was different between test temperatures at 1000 ∘C and 1050 ∘C. Moreover, the relationship between the minimum creep rate and stress was different at the various temperatures. The stress exponent values at 1000 ∘C and 1050 ∘C, were n = 6 and 12 respectively. This difference was due to differences in the formation of dislocation network. At 1000 ∘C, when the minimum creep rate, the dislocation network formed completely independent of stress level. On the other hand, at 1050 ∘C, the dislocation network had not developed fully at the minimum creep rate and the formation of dislocation network depended on the stress level. Therefore, stress dependency at 1050 ∘C is higher than that at 1000 ∘C