The plastic strengthening effect after long-term endurance and fatigue verification of aero-engine turbine blade single crystal superalloy

摘要

The elastoplastic behaviors of a nickel-based single crystal superalloy at 760 degrees C, 927 degrees C and 1100 degrees C were studied, respectively, after 815 degrees C/250 MPa lasting for 2000 h, 927 degrees C/205 MPa lasting for 2000 h and 1100 degrees C/30 MPa lasting for 1000 h. After 815 degrees C/250 MPa lasting for 2000 h, the gamma' phases still maintain the cubic shape, but their size increases compared with the original microstructure. The values of sigma(b), sigma(0.2), delta(5) and psi increase. The tensile fracture surface is 45 degrees with the [001] direction and the fracture mechanism is octahedral slip. After 927 degrees C/205 MPa lasting for 2000 h and 1100 degrees C/30 MPa for 1000 h, N-type plate-like rafting structure formed, and the latter owns a higher degree. The values of sigma(b) and sigma(0.2) decrease obviously, while d5 and. basically are unchanged. The mechanism is the mixed fracture of octahedral slip and I-type. The fatigue verification test and simulation further prove the strengthening effect.

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