Effect of film-hole configuration on creep rupture behavior of a second generation nickel-based single crystal superalloys

•We present both the experimental and numerical results regarding the film-hole configuration effects on the creep rupture behavior of a second generation nickel-based single crystal superalloy DD6.•A new factor was introduced in this paper to quantitatively characterize the stress multiaxiality.•Variety of high temperature oxidation products were observed on the surface of the specimens.

Thin-walled specimens with different film-hole configurations were used to model a second generation nickel-based single crystal superalloy. The effect of film-hole configuration on the high temperature creep rupture behavior of the superalloys was experimentally studied at 980 °C/300 MPa. A creep numerical model based on the crystal plasticity theory was built and implemented into a finite element procedure. A new factor was introduced in this paper to quantitatively characterize the stress multiaxiality. Experimental results show that one- and two-row specimens exhibit longer lives than those without film-holes. However, the creep rupture life decreases with the increase of film-hole rows. Stress distribution of different types of specimens was obtained by finite element analysis (FEA). Numerical results reveal that the existence of film-holes causes stress concentration and changes local stress from uniaxial to multi-axial. A variety of high temperature oxidation products were observed on the surface of the specimens, which could be a detrimental factor contributing to creep rupture. Numerical results were consistent with the fracture position and morphology of specimens of the experiment.

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