Theory and experiment study on stress rupture properties of nickel-based single crystal cooling blades

Thin-walled plate specimens with 0~4 rows of film cooling holes were used to simulate the air-cooled turbine blades. The effect of holes distribution on the lifetime until the stress rupture of nickel-based single crystal cooling blades was studied. Based on the crystal plasticity theory, a creep numerical model for single crystal materials was established, which was implemented into the Abaqus user subroutine. Finite element analysis(FEA)was carried out for specimens with different distribution forms of cooling holes. Experimental results show that with the same number of holes on DD6 specimens, the more rows of the holes are, the shorter stress rupture lifetime specimens it has. Moreover, with the increase of rows number, the descending of creep properties gradually accelerates. Power function models based on FEA data were developed to predict the creep life of the samples with a certain amount of cooling holes under predetermined temperature and loading conditions. The fractional errors of the results are all within 3%. Stress distribution results obtained by FEA coincide with the fracture position and the shape of samples after experiments.