基于激光超声表面波的模具微裂纹无损检测的研究

Research on Non-destructive Testing of Mold Micro Crack Based on Laser Ultrasonic Surface Wave

在现代工业的生产中,模具质地的好坏直接关系到所生产的产品质量。为了获取模具质地的信息,将声表面波与激光超声检测技术相结合,利用声表面波在介质深度不同的表面层传播时,振幅随深度的增加迅速衰减,提出了一种新的模具无损检测方法。由于激光源可以聚焦成点光源(或线光源),使得所获得的波形能够对小和薄的模具进行有效的检测,可以扩展至传统的检测方法的检测盲区内。通过实验分析知,其对材料性能表征和对材料表面和亚表面微小缺陷高度敏感,非常适用于微缺陷的无损检测。

In modern industrial production, mold texture has a direct bearing on the quality of the products. In order to obtain the information,about the mold texture, a new non-destructive mold detection method is proposed, which combines the surface acoustic wave and laser ultrasonic detection technology, and based on the fact that the amplitude declined rapidly with depth increasing when the surface acoustic wave traveled in the medium depth of the surface layer. As the laser light sources can be focused into a point （or line source）, the waveform can be obtained for small and thin mold testing. This method can be extended to the traditional detection in detecting blind spots. From experimental analysis, it is known that it is highly sensitive to the properties of the materials characterization, surface and sub-surface micro-defects and very suitable to non-destructive detection of micro-defects.