针对特种焊接构件中缺陷取向与检测面垂直的情况，采用超声衍射时差技术(TOFD)，对搅拌摩擦焊(FSW)焊缝中的缺陷进行识别和可视化检测，开展搅拌摩擦焊焊缝超声TOFD检测与缺陷评估方法研究。建立了FSW缺陷判别方法，实现了焊接工艺参数的优化，确保了焊缝质量，对FSW的推广和应用具有重要的意义和实际生产价值。

This paper discusses a type of ultrasonic testing technology, Time-of-Flight-Diffraction(TOFD for short), to detect the special welding defects vertical to the test surface. This technology focalizes on the recognition and visual detection of welding defects in Friction Stir Welding(FSW for short), and carry out the assessment methods of TOFD on FSW. Through weld NDT research, we establish FSW defect discrimination method to optimize the welding parameters and improve weld quality. This is good for the promotion and application of FSW.