一种基于激光超声的薄层金属材料厚度检测方法研究

Thickness measurement for thin metal material with the use of laser generated ultrasound

针对传统超声测厚法声波频率低、衰减大,难以检测薄层材料厚度的问题,提出一种基于激光超声的薄层材料厚度检测新方法。该方法所用激光超声波中心频率高、衰减小,可实现声波的非接触式激发与接收,厚度检测精度高;提出一种超声回波信号特征量提取方法,能精确获取声波在薄层材料内传播时间,进一步减小了厚度检测误差。搭建试验系统对不同厚度铝合金试样块进行检测,试验结果验证了该方法的可行性。

Traditional ultrasonic technique is failed in measuring the thickness of thin metal for its limitations in limited frequency domain and high attenuation rate. In this work,a novel approach for measurement of thin metal material thickness was presented to solve the problem. The given approach is more suitable in thickness measurement for its broader frequency domain and lower attenuation rate. A new signal feature extraction method was presented at the same time to gain the travel time of the waves. An example of the approach and experimental measurement was given for alloy with different thickness. The experimental results show the reliability of the approach.