由于工件安装的特殊性，需对直径很小、长度较长的弹性轴采用端部入射法进行超声波检测。常规超声波检测由于灵敏度低、侧壁干扰严重、分辨率低、端部盲区大等局限，检测效果通常较差。采用超声波相控阵技术，通过对聚焦深度及扫查角度的精确控制，获得了很好的检测效果。

Because of the special installation of the work-piece, it is necessary to perform ultrasonic testing of the elastic shaft with small diameter and long length by the end-incidence method. Due to the limitation of low sensitivity, serious side-wall interference,low resolution and large blind end area, conventional ultrasonic detection results are not so satisfied. In this paper, the ultrasonic phased array technique is used to control the focusing depth and scanning angle accurately, and the detection effect is very good.