Analysis of thin-wall effect mechanism based on stress rupture properties and fracture characteristics of DD10 Ni-based single-crystal alloy

The stress rupture life and fracture characteristics of DD10 nickel-based single crystal alloy with different wall thicknesses were investigated. Stress rupture tests were performed on samples with wall thicknesses of 0.8 mm and 0.5 mm at 1000 °C/200 MPa and 1150 °C / 100 MPa. According to the experimental results, the thin wall effect was observed at both 1000 °C / 200 MPa and 1150 °C / 100 MPa. XRM (X-ray microscope) results show a larger proportion of large size cracks/voids in the 0.8 mm wall samples than in the 0.5 mm wall samples. Meanwhile, the C* values are smaller in the thicker wall samples than in the thinner wall samples for the same crack length. Combining the results of XRM and C* results speculate that a longer crack length and propagation time is required to achieve unstable propagation in thicker walled samples. This is one of the important reasons for the thin-wall effect.