针对薄板检测的特殊性，运用Snell公式等分析计算设计了一种超声相控阵斜探头楔块，并采用声场模拟以及实际检测方法验证了设计的楔块对于薄板搅拌摩擦焊缺陷的检测效果。结果表明，采用上述方法可以优化楔块设计，减少盲目性。按照设计结果加工的楔块对薄板具有良好的检测效果，可检测出3 mm板中距离上表面1 mm直径为0.3 mm的侧孔。

Considering the specificity of thin metal plate, an ultrasonic phased array wedge is developed by computing and analyzing with Snell’s law. By means of sound field simulation and actual test, the effect of the wedge for testing defect in friction stir welds is proved. It proves that with this method the design of wedge can be optimized and can get rid of blindness. The wedge made according to the design shows great effect, which can detect the lateral hole locating 1mm under the upper surface whose diameter is 0.3 mm in the 3 mm plate.