涂层性能的超声无损检测与表征技术研究

发布时间：2018-06-04 07:42

本文选题：涂层性能 + 超声检测　；参考：《北京理工大学》2015年硕士论文

【摘要】：随着各类涂层技术的发展及其应用,为了避免或减少因其失效对基底造成的破坏和损失,涂层性能的检测与评价方法越来越受到研究人员的重视。超声无损检测技术能实现非破坏性、自动化检测,且具有检测过程简单、效率高的优点,使其能成为涂层性能检测的有效手段。本文主要在掌握涂层声学特性及超声波在其中传播规律的基础上,研究利用超声法对涂层性能检测中涂层厚度及其均匀性、涂层结合质量这两大难题进行无损检测与表征的方法。对于涂层厚度及其均匀性检测难题,基于超声波在涂层中的传播规律,提出利用Welch谱估计对涂层厚度进行超声无损测量的方法,该测量方法结果与显微测量法结果的相对误差小于6%。在此基础之上,利用C#与Matlab混合编程技术将该厚度算法融入到超声显微系统的C扫功能中,通过离散的颜色值来表示涂层的厚度,实现涂层厚度分布的C扫成像,并通过对图像的分析达到对厚度均匀性进行无损评估的目的。涂层结合质量检测与表征难题主要包含涂层结合缺陷检测、涂层结合强度表征两个方面。对于涂层结合缺陷,采用底面回波反射法实现对人工制造的涂层结合界面缺陷进行检测。对于涂层结合强度,利用底面回波反射技术及非线性超声技术测量对涂层结合强度敏感的超声特征参数,建立并分析所选择特征参数与力学法测量得到的结合强度的关系,实现涂层结合强度的超声无损表征。
[Abstract]:With the development and application of all kinds of coating technology, in order to avoid or reduce the damage and loss caused by its failure on the substrate, more and more researchers pay attention to the testing and evaluation methods of coating performance. Ultrasonic nondestructive testing (NDT) technology can realize non-destructive, automatic testing, and has the advantages of simple testing process and high efficiency, which makes it an effective means of coating performance testing. On the basis of mastering the acoustic characteristics of the coating and the law of ultrasonic propagation in the coating, the thickness and uniformity of the coating are studied by using the ultrasonic method. Methods of nondestructive testing and characterization of coating bonding quality. For the difficult problem of measuring coating thickness and its uniformity, based on the propagation rule of ultrasonic wave in coating, a method of ultrasonic nondestructive measurement of coating thickness using Welch spectrum estimation is put forward. The relative error between the results of this method and that of microscopic measurement is less than 6. On this basis, the thickness algorithm is integrated into the C scan function of ultrasonic microscopy system by C # and Matlab mixed programming technology. The thickness of the coating is expressed by discrete color values, and the C scan imaging of the thickness distribution of the coating is realized. The non-destructive assessment of thickness uniformity is achieved by image analysis. The problems of coating bonding quality testing and characterization mainly include coating bonding defect detection and coating bonding strength characterization. For coating bonding defects, the bottom echo reflection method is used to detect the artificial coating bonding interface defects. For coating bonding strength, ultrasonic characteristic parameters sensitive to coating bonding strength are measured by bottom echo reflection technique and nonlinear ultrasonic technique, and the relationship between the selected characteristic parameters and the bond strength measured by mechanical method is established and analyzed. The ultrasonic nondestructive characterization of the bonding strength of the coating was realized.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB302.5

【共引文献】