陶瓷制品无损检测最佳灵敏度影响因素的研究

红外热成像无损检测的本是测量物体表面的温差，温差越大，同检测灵敏度越高。本文就陶瓷制品红外热成像无损检测影响最佳检测灵敏度的因素进行了研究，发现被检测材料本身的导热系数和缺陷材料的导热系数是最主要的影响因素，而热激发温度或热流和环境温度则是影响红外无损检测重要的外部因素；缺陷在制品内存在的深度、缺陷的尺寸及缺陷的类型则是影响红外检测的重要因素。     

陶瓷的无损检测

本文论述了陶瓷材料缺陷的分类，国内外陶瓷材料无损检测的概况，分析了应用红外热成像技术研究陶瓷制品的无损检测的基本理论，研究方法和检测特点，说明了用红外热成像技术进行陶瓷制品无损检测的可行性。     

红外热成像测温技术在无机非金属材料工业中的应用

应用红外热成像测温技术，对几种陶瓷坯件在烧结过程中温度场的分布进行系统的测试和研究，首次揭示了陶瓷材料在不同温度下的动态温度场，利用计算机处理技术探讨了陶瓷坯体在烧结过程中变形与温度场的关系，并分析了红外热成像技术在无机非金属材料工业中的各种应用，包括动态温度场的测试，设备监控，故障诊断，无损检测，自动控制等。说明了红外热成像 技术在本行业中具有广阔的应用前景。     

红外热波检测技术在微孔丝网复合材料中的应用探讨

微孔丝网复合材料因其特殊的孔隙结构,难以通过常规无损检测手段检查出其制造过程中的分层、开裂等内部缺陷。本文采用红外热波技术开展了微孔丝网复合材料无损检测的应用研究,结果表明:红外热波无损检测技术能够确定材料缺陷的位置和形状,通过解剖发现检出的最小分层开裂宽度6um。实验证明红外热波无损检测技术是一种新型有效的的微孔材料检测方法。     

红外热成像无损检测陶瓷制品机理的研究

红外热成像作为陶瓷制品无损检测的一种工具,无疑具有很多有别于其他检测工具的优点,本文从热传导的角度出发,应用有限元理论,对红外热成像无损检测的过程机理进行分析研究,推导出瞬态热传导问题的数学模型,应用该模型进行计算机模拟,并把模拟的结果和红外热成像仪实测的结果进行比较,表明本数学模型可用以研究及模拟红外热成像的检测过程,为机理的研究创造了条件。     

风电叶片复合材料结构缺陷无损检测研究进展

主要介绍了超声波、声发射和红外热成像等无损检测技术在风电叶片复合材料结构检测中的应用,从而推动我国大型风电叶片全尺寸结构缺陷评价控制和认证体系的形成。     

陶瓷坯体烧成中表面温度场的动态测试

本文应用红外热成像测温技术，在国内首次揭示了几种陶瓷坯体在烧成过程中动态温度场的分布，系统而全面地测试了陶瓷胚体在烧成过程中的温度分布，为研究陶瓷烧结机理及烧结缺陷的产生提供了一定的科学依据。     

无损检测技术在纤维增强聚合物复合材料机械损伤监测中的应用进展

本文综述了近年来应用在纤维增强聚合物复合材料中无损检测技术的研究成果,分析比较了超声波技术、图像处理技术、基于X射线的无损检测技术(X射线摄影、X射线断层摄影技术与X射线暗场成像技术)、红外热成像技术的原理及特性,针对已有的无损检测技术和研究现状,对纤维增强聚合物复合材料无损检测技术未来的发展方向和应用进行了展望。     

复合材料风电叶片静态无损检测方法研究进展

主要对复合材料风电叶片在制造、运输、运行过程中常见缺陷成因进行了分析,对目前国内外可用于叶片全尺寸静态检测的几种无损检测方法发展情况作了概述,指出红外热成像技术、超声波检测技术、射线成像技术、磁检测技术可快速地对复合材料风电叶片进行全尺寸静态检测。     

热观测技术的应用

据《Interceram》报道:在卫生瓷坯体干燥阶段和石膏模制造过程的干燥阶段应用热观测技术,可得知坯体和模具干燥时的表面温差,从而有效地控制干燥过程,大大提高模具和坯体的成型质量。试验表明:坯体在     

陶瓷窑炉动态温度场测试及操作的优化

利用先进的红外热成像测试技术及自动设计的断面温差测试系统,进行了陶瓷窑炉火焰温度场分布的测试,窑墙表面温度场的测试、干燥器干燥效果的测试及窑内同一横断温差分布的测试。研究了影响火焰温度场的各因素,为窑炉的控制及操作的优化提供了可靠的依据。     

基于红外热成像的脉动热管运行及传热特性分析

基于红外热成像技术和高速可视化观测手段,得到了不同热负荷下脉动热管冷凝段表面的温度分布和管内工质的运行状态,分析了两者与热管传热性能间的内在联系。研究表明:随着热负荷的升高,工质准稳定运行状态依次呈现单管小幅脉动、管间大幅脉动和整管单向循环3种模式;冷凝段内主要出现泡状流和塞状流两种流型且离散气泡所占的份额逐渐减小;不同运行模式下工质能质输运强度的差异导致脉动热管冷凝段壁温分布各具特征;冷凝段表面的红外热图像可成为辨识管内工质运行状态和判断热管传热性能优劣的重要依据。     

Evaluation of Ceramic Matrix Composites by Thermal Diffusivity Imaging

Because of the complex structural design and multiple processing steps, ceramic matrix composites (CMCs) typically contain a variety of flaws distributed throughout the volume. These flaws need to be detected and characterized because they are detrimental to CMC material properties. Thermal diffusivity imaging is a nondestructive evaluation method that can quantitatively determine the thermal property of a CMC component. Thermal diffusivity is an intrinsic material property that not only depends on the material constituents but also on the micro- and macrostructure of the CMC component. This paper investigates fundamental theories for thermal diffusivity measurement using pulsed thermal imaging from two- and one-sided setups. The variation of thermal diffusivity is examined for two types of flaws, voids and cracks, that are commonly present within CMCs. The sensitivity of thermal imaging to detect small and large flaws is analyzed and evaluated with measured thermal diffusivity data. In addition, analysis of fracture theories for the mechanical and thermal properties of materials with distributed microcracks has identified that thermal diffusivity may be used to determine the degradation of mechanical properties and, therefore, to predict the remaining life of a CMC component. Preliminary results for correlating thermal and mechanical properties are discussed.     

大液滴撞击结冰传热过程及介质阻挡放电除冰实验研究

对大液滴撞击过冷壁面结冰的传热和相变过程进行了实验研究,采用高速成像技术与红外测温成像技术对液滴撞击不同温度过冷壁面时的动态过程进行拍摄记录。另外提出一种新的除冰方式,利用高频纳秒脉冲介质阻挡放电等离子体激励器进行了除冰的实验验证,并进行了热力学分析。实验结果表明：壁面温度的变化对液滴铺展过程影响较小,最大铺展系数几乎不变,但对液滴收缩与振荡过程以及最终结冰冰形有较大的影响;结冰从液滴底层开始,壁面温度越低,液滴与过冷壁面温差越大,底层液滴结冰更快,而上层液膜经过回缩、振荡之后,液膜厚度更薄,结冰相变所需时间也更短;利用高频纳秒脉冲介质阻挡放电除冰效果显著,其放电区域作用相当于是一个“热源”且根据其作用方式的不同,除冰过程可分为两个阶段。     

Cracking behavior of glazings with different thicknesses by radiant exposure

Fourteen experiments on cracking behavior of glazings with thicknesses of 3, 6, 8, and 10 mm by radiant exposure were carried out with a new experimental apparatus. The radiant power was controlled proportional to time square to simulate a time‐squared growth fire. An infrared thermal imaging camera was employed to monitor the temperature field of the unexposed glazing surface. Other important parameters including incident heat flux, local gas temperature, exposed surface temperature, and time of the first cracking were obtained. The relationship between the cracking behavior and glazing thickness was analyzed based on the experimental results. The results show that the protected edge temperature of glazing has a considerable rise when the first cracking occurred, which should be included in further modeling. It was also shown that thicker glazings have smaller surface temperature during the heating process and induce longer time to first crack. However, the critical temperature difference approximately remains constant for all glazings studied. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis and characterization of itaconic anhydride and stearyl methacrylate copolymers

The free-radical copolymerization and the properties of comb-like copolymers derived from renewable resources, itaconic anhydride (ITA) and stearyl methacrylate (SM), are described. The ITA-SM copolymers were nearly random with a slight alternating tendency. The copolymers exhibited a nanophase-separated morphology, with the stearate side-chains forming a bilayer, semi-crystalline structure. The melting point (T_m) of the side-chains and the crystallinity decreased with increasing ITA concentration. The crystalline side-chains suppressed molecular motion of the main chain, so that a glass transition temperature (T_g) was not resolved unless the ITA concentration was sufficiently high so that T_g > T_m. The softening point and modulus of the copolymers increased with the increasing ITA concentration, but the thermal stability decreased.     

Using infrared thermography to analyze substrate and adhesive effects in bonded structures

This study was focused on the application of infrared thermography for assessment of technological procedures used to improve adhesion in bonded structures. Infrared thermography is a remote imaging technique which can be fruitfully exploited either for mapping surface temperature in temperature-dependent manufacturing processes, or for nondestructive evaluation of end products. Basically, for nondestructive evaluation two different approaches are possible: traditional pulse thermography (PT) and lock-in thermography (LT) and the use of both techniques is discussed. Several specimens were fabricated to simulate different bonded structures that are used mainly in the aerospace industry. Such bonded structures included: adhesively-bonded aluminum joints with or without surface treatment before bonding, glass-reinforced epoxy composites and carbon-reinforced epoxy composites with or without plasma treatment before bonding. Pulse and lock-in thermographies are both capable of visualizing inhomogeneities in bulk materials, as well as disbonding, delamination, flaws and foreign inclusions in bonded structures. The results show that lock-in thermography is also capable of evaluating the effect of adhesive thickness and the effects induced in bonded structures by substrate surface treatments.     

稠油热采保温管线外表面发射率获取方法及实验

稠油热采保温管线外表面发射率是表征辐射本领的物理量,是一项很重要的热物性参数。利用红外热像仪测温原理的通用基本公式推导出发射率的数学模型,得出两种管线外表面发射率的测量方法,对两种方法进行了室内实验验证。通过实验研究了有人工太阳辐射和没有人工太阳辐射对管线外表面发射率测量的影响。结果表明人工太阳辐射对发射率的影响较大,两种计算发射率方法中,得出管线外表面发射率误差值分别为37.5%和25%。