太赫兹脉冲光谱法测量微米级多层油漆涂层厚度技术

发布时间：2018-02-15 02:22

本文关键词： 太赫兹脉冲光谱法飞行时间多层涂层厚度非接触均匀性　出处：《光谱学与光谱分析》2017年11期 　论文类型：期刊论文

【摘要】：在汽车工业、飞机、船舶等领域中,油漆的涂层厚度管理对产品防水、防锈功能和颜色效果有着重要影响,但是目前采用的商业化涂层测厚仪都是接触式,并且很难直接获得多层涂层中的各层厚度。利用反射式太赫兹时域光谱(THz-TDS)系统探测样品的太赫兹脉冲光谱,基于脉冲回波的飞行时间建立简易的单点漆膜厚度提取模型。并通过最小二乘法拟合油漆样品的光学厚度与几何厚度之间的线性关系计算出12种涂覆在铝板上的油漆样品的测量折射率,发现金属油漆与非金属油漆在太赫兹波段的折射率存在较大的差异,闪光银色油漆样品的测量折射率为5.15,而白色油漆样品的测量折射率仅为2.64。在单层白色油漆样品厚度分布均匀的区域内测量50个点的膜厚,以磁/涡流感应涂层测厚仪的测量数据为参考标准,得到的厚度平均值为71.7μm,测量误差为3.5μm。对双层油漆样品进行二维扫描,测得白色油漆和底漆的厚度分布分别是(233±13)和(130±11)μm。同样,通过黑色三层油漆样品和银色三层油漆样品的二维分布图,分析了各层的漆膜厚度及其分布的均匀性。结果表明,太赫兹脉冲光谱法实现了1~3层漆膜的厚度测量及其分布均匀性评估,该方法对金属油漆的厚度分辨力较高,并且可通过非接触探测样品的太赫兹脉冲光谱,获得多层油漆的各层厚度及厚度的二维分布信息,易于实现喷涂质量的评估。
[Abstract]:In the automotive industry, aircraft, ships and other fields, coating thickness management has an important impact on product waterproof, rust prevention function and color effect, but the current commercial coating thickness meter are all contact. And it is difficult to obtain the thickness of each layer in the multilayer coating directly. The THz pulse spectrum of the sample is detected by the reflection THz time domain spectroscopy (THz) system. Based on the time of flight of pulse echo, a simple single point film thickness extraction model was established, and the linear relationship between the optical thickness and geometric thickness of paint samples was fitted by the least square method. Twelve kinds of coatings coated on aluminum sheet were calculated. The refractive index of the paint sample, It is found that the refractive index of metallic paint and nonmetallic paint is quite different in terahertz band. The refractive index of a flash silver paint sample is 5.15, while that of a white paint sample is only 2.64.The thickness of the film is measured at 50 points in an area where the thickness of the single layer white paint sample is uniformly distributed. Taking the measurement data of magnetic / eddy current induction coating thickness meter as reference standard, the average thickness is 71.7 渭 m and the measurement error is 3.5 渭 m. The thickness distributions of white paint and primer are 233 卤13) and 130 卤11 渭 m, respectively. Based on the two-dimensional distribution of black and silver paint samples, the film thickness and its distribution uniformity of each layer are analyzed. Terahertz pulse spectrum method has been used to measure the thickness and evaluate the uniformity of the coating film. The method has high resolution to the thickness of metal paint, and can detect the THz spectrum of samples by non-contact detection. The two-dimensional distribution information of each layer thickness and thickness of multi-layer paint is obtained, which is easy to realize the evaluation of spray quality.
【作者单位】：天津大学精密测试技术及仪器国家重点实验室;天津大学太赫兹中心;
【基金】：科技部重大仪器专项(2011YQ15002105)资助
【分类号】：O657.3;TQ630.79

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