对影响材料发射率的因素和发射率模型的探究

发布时间：2018-04-24 07:22

本文选题：发射率 + 氧化和氮化　；参考：《河南师范大学》2017年硕士论文

【摘要】：发射率是物体的热物性参数之一,是描述物体的热辐射特性的重要参数,在航空、航天、科学研究,国防和工农业生产等领域中具有重要的应用价值和研究意义,其测量精度水平、大小控制、变化特征控制是测量各种相关产品质量的重要技术指标,发射率的测量在红外测量技术中占据着重要地位。发射率的测量受波长、温度、发射角、表面粗糙程度、表面氧化程度、是否有污染物以及样品成分的影响,发射率很难精确测量。在表面状态不同时,测量发射率随波长和温度的变化就更难了。尤其是样品表面长时间被空气氧化,测量发射率随波长和温度的变化可能就变得更加复杂。在本文中我们详细探究了在波长为1.5μm时,钛和钛合金在800-1100K的温度范围内发射率随着温度和加热时间的变化,讨论了样品表面氧化和氮化对发射率的影响,在1.4-2.1μm的波长范围和800-1100K的温度范围内,为了精确预测不锈钢304的温度,测试了九种发射率模型。钛TA2和钛合金Ti-6Al-4V由于高拉伸强度和高强度重量比,耐热,耐腐蚀性能和低密度的优势,广泛应用在航空航天、汽车、国防、医疗和化工行业等各个领域。在所有的应用中,钛TA2和钛合金Ti-6Al-4V的发射率都是一个关键参数。毫不夸张地说,钛TA2和钛合金Ti-6Al-4V的发射率的测量和估值已经成为一些应用中的重要挑战。例如,在航空和飞机构件,发射率的值必须是在传热时进行计算。用钛合金Ti-6Al-4V制作航空和飞机的部件时,经常涉及高温过程,甚至是在融化状态。此时,在无触头温度测量的过程中发射率是正确测量温度的一个基本参数;在校准检验激光金属沉积过程模型中,光谱发射率也是必要的。然而,钛TA2和钛合金Ti-6Al-4V的发射率值相当缺乏,只存在于少数文献报告中。在文章的前一部分,我们主要补充了钛TA2及钛合金Ti-6Al-4V的发射率数值。辐射测温可以分为单波长测温法和多谱线辐射测温法。利用单波长测温法时,为了能精确的测量温度,我们必须知道样品准确的光谱发射率。利用多谱线辐射测温法时,我们对光谱发射率、波长、温度都必须有充足的知识储备。我们已经分析过许多实验来研究不锈钢钢表面氧化层增长所引起的光谱发射率的变化。我们早期的论文指出,不锈钢表面氧化能很大程度上影响光谱发射率并带来明显的温度测量误差。温度测量的精确度很大程度上依赖于多谱线辐射测温法所确定的发射率模型。表面氧化是否影响光谱发射率模型?在本文中我们将回答这个问题。最后,通过对实验所得数据的对比分析,我们对钛TA2、钛合金Ti-6Al-4V及不锈钢304的发射率值进行了补充,得出了许多重要的结论,对工业生产和应用具有重要意义。
[Abstract]:Emissivity is one of the thermal physical parameters of objects, and it is an important parameter to describe the thermal radiation characteristics of objects. It has important application value and research significance in the fields of aviation, aerospace, scientific research, national defense and industrial and agricultural production, etc. The measurement accuracy level, size control and variation feature control are important technical indexes for measuring the quality of various related products. Emissivity measurement plays an important role in infrared measurement technology. The emissivity measurement is difficult to accurately measure because of the influence of wavelength, temperature, emission angle, surface roughness, surface oxidation, contaminants and sample composition. At different surface states, it is more difficult to measure emissivity with wavelength and temperature. Especially when the surface of the sample is oxidized by air for a long time, the change of emissivity with wavelength and temperature may become more complicated. In this paper, we have studied the change of emissivity of titanium and titanium alloy with temperature and heating time in the temperature range of 800-1100K at the wavelength of 1.5 渭 m. The effects of surface oxidation and nitridation on the emissivity are discussed. Nine emissivity models were tested in the wavelength range of 1.4-2.1 渭 m and the temperature range of 800-1100K in order to accurately predict the temperature of 304 stainless steel. Titanium TA2 and titanium alloy Ti-6Al-4V are widely used in aerospace, automobile, national defense, medical and chemical industry due to their advantages of high tensile strength and high strength to weight ratio, heat resistance, corrosion resistance and low density. The emissivity of titanium TA2 and titanium alloy Ti-6Al-4V is a key parameter in all applications. It is no exaggeration to say that the measurement and estimation of emissivity of titanium TA2 and titanium alloy Ti-6Al-4V have become important challenges in some applications. For example, in aeronautical and aircraft components, the emissivity must be calculated during heat transfer. Titanium alloy Ti-6Al-4V often involves high temperature processes, even melting state, in the manufacture of aircraft and aeronautical components. In this case, emissivity is a basic parameter for measuring temperature correctly in the process of non-contact temperature measurement, and spectral emissivity is also necessary in calibrating the model of laser metal deposition process. However, the emissivity values of titanium TA2 and titanium alloy Ti-6Al-4V are rather short, and are only reported in a few literatures. In the first part of this paper, we mainly supplement the emissivity of titanium TA2 and titanium alloy Ti-6Al-4V. Radiation temperature measurement can be divided into single wavelength temperature measurement method and multi-spectral line radiation temperature measurement method. In order to measure the temperature accurately, we must know the accurate spectral emissivity of the sample. We must have sufficient knowledge of spectral emissivity, wavelength and temperature when using multi-line radiometric temperature measurement. We have analyzed many experiments to study the variation of spectral emissivity due to the growth of oxidation layer on the surface of stainless steel. It is pointed out in our earlier paper that the surface oxidation of stainless steel can greatly affect the spectral emissivity and bring about obvious temperature measurement errors. The accuracy of temperature measurement depends largely on the emissivity model determined by multi-spectral line radiometry. Does surface oxidation affect the spectral emissivity model? We will answer this question in this article. Finally, the emissivity values of titanium TA2, titanium alloy Ti-6Al-4V and stainless steel 304 are supplemented by comparing and analyzing the experimental data, and many important conclusions are drawn, which are of great significance for industrial production and application.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.2

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