气膜孔孔形对 CMSX-10 平板试样蠕变性能的影响

Three types of film holes with inclination and yaw angles， namely circular holes，expansion holes，and W-shaped holes，were designed to study the creep properties of the third-generation nickel based high-temperature alloy CMSX-10 with the cooling blade simulation specimens. High temperature creep tests were conducted to investigate the effect of hole shape on the rupture life of simulation specimens. The results showed that，the rupture life of the circular hole specimen was about 1.3 times that of the expanded hole specimen，and the rupture life of the expanded hole specimen was about 1.3 times that of the W-shaped hole specimen under the average stress of 350 MPa and temperature of 980 ℃. Combined with scanning electron microscopy analysis，it was found that the creep fracture of the sample was a mixed mode of cleavage and dimple fracture caused by stress concentration near the film hole. Based on crystal plasticity theory，simulation analysis was conducted. The simulation results showed stress concentration and redistribution around the film holes. The simulation results can explain the fracture characteristics obtained from experiments. The improved Lemaitre creep damage model and Larson Miller equation were sed to predict the creep fracture life of CMSX-10 flat plate specimens with circular holes. The results showed that the accuracy of predicted creep life based on the improved Lemaitre creep damage model was higher.