基于红外热波技术的金属表面微裂纹检测研究

Research on detection of micro cracks on metal surface based on infrared thermal wave technology

针对传统金属表面微裂纹检测技术存在识别率低、检测成本过高等问题,提出了基于红外热波技术的检测方案。利用红外热波状态函数描述温度场的变化趋势,在非稳定的条件下定位金属构件表面的微裂纹位置和深度;基于红外热像仪采集不同频率、相位的反射波特点,在相空间范围内确定红外热波的矢量变化趋势;以红外热波缺陷特征为基础,生成红外热波图像序列集合,再利用多项式数据拟合的方式处理红外图像像素点随温度的变化趋势。实验结果表明,所提检测方法提取的红外热波微裂纹图像清晰、位置精确,缺陷检测的时间成本更低。

Aiming at the problems of low recognition rate and high detection cost in traditional metal surface micro crack detection technology,a detection method based on infrared thermal wave technology is proposed.The state function of infrared thermal wave is used to describe the change trend of temperature field,and the position and depth of micro cracks on the surface of metal components are located under unstable conditions.Based on the characteristics of reflected waves with different frequencies and phases collected by infrared thermal imager,the vector change trend of infrared thermal wave is determined in the range of phase space.Based on the defect characteristics of infrared thermal wave,the infrared thermal wave image sequence set is generated.Then,the change trend of infrared image pixels with temperature is processed by polynomial data fitting.The experimental results show that the infrared thermal wave micro crack image extracted by the proposed detection method is clear and accurate,and the time cost of defect detection is lower.