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针对镁合金棒材的近中心缺陷和近表面缺陷,分别采用探头垂直入射或偏心入射的超声检测方式,然后运用滤波去噪等信号处理方法对原始信号及特征回波信号进行特征提取,寻找特征信号规则,进而判定缺陷类型,如孔状缺陷、裂纹状缺陷等。利用小波变换原理增强原始信号,使B扫描成像图清晰易辨别,最终根据棒材和B扫描图比例关系,计算出缺陷位置。为合金类构件的缺陷检测提供了一种有效的简单快捷的检测手段。
Aimed at the near-center defects and near-surface defects of magnesium alloy bars, the ultrasonic detection methods of vertical incidence or eccentric incidence of the probe are respectively adopted, and then the signal characteristics of the original signal and the characteristic echo signal are extracted by using signal processing methods such as filtering and denoising, Signal rules, and then determine the type of defect, such as hole defects, crack-like defects. The principle of wavelet transform is used to enhance the original signal so that the B-scan image can be clearly and legibly identified. Finally, the defect position is calculated according to the proportional relationship between the bar and the B-scan image. For the detection of defects in alloy components provides an effective simple and efficient detection means.