Abstract: The single-crystal material of the Ni-based superalloy has excellent comprehensive mechanical properties. The deviation of crystal orientation is one of the main defects in single-crystal blades. In this work, ultrasonic wave velocities are used to evaluate the crystallographic orientation of the Ni single-crystal material. The orientation-dependent refracted field is measured using a linear ultrasonic phased array transducer placed beneath the sample at three in-plane orientations. The refracted field is connected to the crystallographic orientation by reconstructing the velocity surface as a function of Wigner-D function. The proposed method can evaluate three complete Euler angles at one time. To verify the effectiveness of the method, the Ni-based single-crystal samples with different crystal orientations were prepared for ultrasonic measurement and volume average orientation evaluation. A comparison with the Electron Backscattered Diffraction (EBSD) measurements shows that the evaluation error rate of the proposed method is within 3.69%.

Key words: ultrasound, sound velocity, Ni-based single-crystal, crystallographic orientation, Wigner-D functionhttp