铁磁材料表面缺陷的磁光成像检测方法研究

发布时间：2018-03-16 19:09

本文选题：铁磁材料　切入点：无损检测　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：铁磁性材料被广泛应用于各种工程系统中,无损检测技术保障了其安全性和完整性。目前用于铁磁材料无损检测的方法主要是:超声法、涡流法、磁粉法和漏磁法,这些方法的检测结果不够直观,而缺陷可视化是未来的发展趋势。磁光成像法结合了涡流效应和法拉第磁光效应,具有快速、实时、大面积、可视化的优势,逐渐成为无损检测领域的研究热点,但将磁光成像法用于铁磁材料缺陷检测的研究很少。本文针对现有铁磁材料缺陷检测方法存在的不足,结合已有大量磁化装置的事实,提出基于漏磁的磁光成像法,用于铁磁材料缺陷的检测,并设计、搭建实验平台,通过获取图像对比光强,验证其可行性。首先,详细阐述了磁光成像法的国内外研究现状和基本原理,分析了将磁化铁磁材料时缺陷处的泄露磁场与法拉第磁光效应结合的可行性。然后,从磁场产生方式、光路、磁光传感器三个方面对比了国内外两个典型的磁光成像方案,找出优缺点并设计了基于漏磁的磁光成像实验平台。对磁铁、磁光传感器、激光光源、扩束镜、偏振片和图像传感器等重要部件进行了选型。给磁光传感器的上下表面分别镀了抗反射膜和反射膜,并定性分析了磁光传感器加膜对光传播和缺陷成像的影响。最后,搭建了磁光成像实验平台,制作硅钢片表面缺陷进行实验并获取缺陷处图像,验证了基于漏磁的磁光成像法用于铁磁材料表面缺陷检测的可行性,为进一步探究其用于亚表面缺陷可视化检测及定量分析打下了基础。
[Abstract]:Ferromagnetic materials are widely used in various engineering systems, and the nondestructive testing technology guarantees their safety and integrality. At present, the methods used in nondestructive testing of ferromagnetic materials are ultrasonic, eddy current, magnetic powder and magnetic flux leakage. The results of these methods are not intuitive enough, but defect visualization is the development trend in the future. Magneto-optic imaging method combines eddy current effect and Faraday magneto-optic effect, and has the advantages of fast, real-time, large area and visualization. It has gradually become a hot spot in the field of nondestructive testing, but there is little research on the application of magneto-optic imaging method to the defect detection of ferromagnetic materials. In this paper, in view of the shortcomings of the existing methods of defect detection of ferromagnetic materials and the fact that a large number of magnetization devices have been developed, A magneto-optic imaging method based on magnetic flux leakage (MFL) is proposed to detect defects in ferromagnetic materials. An experimental platform is designed and built to verify the feasibility of the method. The present research situation and basic principle of magneto-optic imaging at home and abroad are described in detail, and the feasibility of combining the leakage magnetic field at defects in magnetized ferromagnetic materials with Faraday magneto-optic effect is analyzed. This paper compares two typical magneto-optic imaging schemes at home and abroad in three aspects, finds out the advantages and disadvantages, and designs a magneto-optic imaging experimental platform based on magnetic flux leakage. Some important parts, such as polarizer and image sensor, are selected. The anti-reflection film and reflection film are plated on the upper and lower surfaces of magneto-optic sensor, and the effect of magneto-optic sensor film on optical propagation and defect imaging is analyzed qualitatively. The experiment platform of magneto-optic imaging is built, the surface defect of silicon steel sheet is tested and the image of defect is obtained, which verifies the feasibility of magneto-optic imaging method based on magnetic flux leakage to detect the surface defect of ferromagnetic material. It lays a foundation for further exploring its application in visual detection and quantitative analysis of subsurface defects.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM271.2

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