基于隔离薄膜的粗糙面磁粉检测方法

Magnetic Particle Testing for Rough Surfaces Based on Lift-Off Layer

中文关键词:  无损检测  磁粉检测  隔离薄膜  缺陷

英文关键词:non-destructive testing  magnetic particle testing  lift-off layer  defects

中文摘要:

      磁粉检测具有灵敏度高、适应性强等优点，但工件表面粗糙会造成伪磁痕，干扰缺陷磁痕的识别，降低准确性。针对该问题，提出一种基于隔离薄膜的磁粉检测方法以增强粗糙表面缺陷的检测能力。利用COMSOL仿真软件分析了隔离薄膜的提离对磁痕的影响，对比不同提离值下的增强效果，分析得出一定厚度的隔离薄膜对磁痕的增强效果最好。选用黄铜金属薄带开展实验，利用平均灰度比评价磁痕图像，比较了不同厚度的隔离薄膜的增强效果，传统方法的平均灰度比结果为1.12，本方法的平均灰度比在隔离膜厚度为0.15 mm时最高，为1.59，是传统方法的1.42倍。此外，实验得出本方法对缺陷深度变化的响应灵敏度约为传统方法的10倍，区分不同深度缺陷的能力得到了提升。

英文摘要:

      Magnetic particle testing(MT) has the advantages of high sensitivity and adaptability,but the roughness of the workpiece surface can cause pseudo-magnetic indication,which interferes with the identification of defective magnetic indication and reduces the accuracy.To address this problem,an MT method based on a lift-off layer(MTLL) is proposed to enhance the ability to detect defects on rough surfaces.COMSOL simulation software is used to analyze the effect of the lift-off layer on the magnetic indication,and the enhancement effects under different lift-off values are compared.The analysis shows that the enhancement is the strongest under certain lift-off values.Thin brass band is used for experiment,and the magnetic indication image is evaluated by using average gray ratio(AGR)to compare the enhancement effects under different lift-off values.The traditional AGR of MT is 1.12,while the AGR of MTLL is 1.59 when the lift-off value is 0.15 mm,which is 1.42 times that of MT.In addition,the experiment shows that the response sensitivity to the defect depth changes is about 10 times higher than the MT,which improves the ability to distinguish defects at different depths.