搅拌摩擦焊焊缝未焊透缺陷的超声相控阵检测

Ultrasonic Phased Array Inspection Technology for Lack of Penetration Weld-defects in Friction Stir Welding

采用A扫加S扫的超声相控阵检测模式对铝合金搅拌摩擦焊焊缝未焊透缺陷进行检测,研究了检测方向和未焊透长度对检测信号的影响,分析了不同未焊透长度超声相控阵检测图像的灰度共生矩阵纹理特性。结果表明,在返回边进行超声相控阵扫查其检测效果更佳;对于长度大于超声检测灵敏度的搅拌摩擦焊未焊透缺陷,随未焊透长度的增加,检测信号幅值相应增加;灰度共生矩阵的二阶矩参数可用来识别是否为未焊透缺陷,而对比度和相关性参数可有效判断未焊透缺陷长度。

Ultrasonic phased array inspection with A-scan plus S-scan scanning mode was used to detect the lack of penetration(LOP)weld-defects in friction stir welding,and the influence of the scanning direction and LOP length on the detection signal were studied,the gray level co-occurrence matrix(GLCM)texture features were extracted and analyzed for ultrasonic phased array inspection images of the different length LOP.The results show that the better effect can be obtained when the ultrasound injects from the beam backward side.When the length of vertical LOP is larger than the ultrasonic detection sensitivity,the amplitude of the signal is proportional to the length of the LOP.The GLCM second-order moment can be used to identify the LOP,and the length of the LOP can be effectively evaluated by the GLCM contrast and relevance parameters.