基于超声声速法的镍基单晶材料晶体取向评价

Measuring crystallographic orientation of Ni-based single-crystal materials using ultrasonic velocity method

镍基高温合金单晶材料具有优异的综合力学性能,单晶叶片等构件中的晶体取向偏离是其主要缺陷之一,针对镍基单晶材料晶体取向开展了超声无损评价方法研究,利用声波在立方各向异性材料中的传播性质,以线性超声相控阵作为接收端测量各向异性材料中与方向相关的折射场,构造了基于Wigner-D函数的空间声速曲面重构算法,进一步建立了晶体取向的声速法评价模型,可一次性评价完整的3个欧拉角。为验证方法有效性,制备了具有不同晶体取向的镍基单晶样品进行超声实验测量和样品的体平均取向评价,并与电子背散射衍射(EBSD)法进行了结果对照。结果表明,本文方法评价误差率在3.69%以内。

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%.