陶瓷基复合材料无损检测研究进展

陶瓷基复合材料的各向异性和不均匀特性,以及在航空航天领域应用的紧迫性,使得采用无损检测(NDT)方法对其进行质量控制及保证是个非常重要而艰巨的任务.综述了陶瓷基复合材料无损检测的发展现状,阐释了超声波、红外热成像和工业CT技术的检测原理及其在陶瓷基复合材料无损检测的应用进展.     

木塑复合材料力学性能的无损检测

采用纵向共振实验、弯曲振动实验等振动方法对木塑复合材料的力学性能进行了无损检测，并对检测结果进行了分析．研究表明，木塑复合材料的动态弹性模量可以通过无损检测方法测量．木塑复合材料的动态弹性模量随着木塑比的减小而降低；而对于同一木塑比的木塑复合材料，利用各种无损检测法测得的动态弹性模量值相差不大。木塑复合材料的动态弹性模量大于静态弹性模量MOE，且有一定的比值；应用这一比值关系可由动态弹性模量估算静态弹性模量．利用动态的无损检测法测得的弹性模量与静态的破损检测法测得的静曲强度MOR具有密切的相关性；其中，纵向共振实验测得的弹性模量Ep与MOR的相关系数最高；应用相关方程可由动态弹性模量估算静曲强度。     

直升机复合材料无损检测技术

由于复合材料在直升机上的大量应用,为满足设计质量上的要求,必须有相应的无损检测技术和无损评估方法,对直升机复合材料构件类型和相关缺陷的特点、直升机复合材料无损检测要求、目前开展直升机复合材料构件无损检测方法及应用、展望直升机复合材料无损检测技术的发展作一阐述。     

无损检测技术在装备中的应用

无损检测技术对构成系统的部件进行检测，确保装备可靠性，避免损失，提高部队战斗力，节约经费。本文介绍了无损检测技术在装备硷测中的作用，以及现代无损检测技术的发展，介绍了红外热成像法、超声检测法、涡流法和磁检测法在无损检测中的应用，并阐明了各种方法的优劣及适用领域。     

压力容器无损检测技术的探讨

介绍了无损检测的几种方法,并进一步说明了这几种检测方法的使用范围及优缺点,着重分析了射线检测法与超声波检测法之间的关系及这两种方法使用时应注意的事项.     

复合材料制件拐角部位超声检测技术

复合材料在航空、航天等领域应用不断增加,制件的结构形式越来越复杂,在很多复杂结构中存在拐角部位,这些拐角部位的检测给无损检测带来困难.通过对资料的分析和试验,介绍了解决复合材料制件复杂结构拐角部位无损检测的方案和思路,并对比分析了各种检测方法的优缺点,认为超声相控阵技术在未来复合材料拐角部位无损检测上具有比较好的应用前...     

钛/钢复合板设备覆层盖板焊缝的检测方法

介绍了钛/钢复合板设备钛覆层盖板焊缝6种检测方法(肉眼观察法、无损检测法、通气检查法、氨气检漏法、氦气检漏法和热气循环检测法)的检测原理.具体操作步骤以及各种检测方法的利弊.指出对于在常温、常压下盛装无毒、不易燃的储罐、储槽类设备优先选择肉眼观察法,不能满足时再依次选择无损检测法和通气检测法即可满足要求;对于被检设备使用温度高于80℃,且操作压力大于0.6 MPa或盛装有毒介质时,应视具体情况依次增加氨气检漏法和氦气检漏法;对于被检设备使用温度超过180℃或温差变化大除进行前述2种情况的检测外,最好应增加热气循环检验,以保证检测的可靠性.     

C/C复合材料的无损检测研究

C/C复合材料综合了碳材料优良的高温性能和复合材料优异的力学性能,它既可以作为功能材料,又可以作为高温结构材料使用,是目前唯一可用于2800℃高温的复合材料.无损检测是材料质量与安全保证的可靠手段,作为新型的结构材料,C/C复合材料的无损检测研究具有十分重要的意义.介绍了近年来有关C/C复合材料的无损检测研究的进展情况,并评价了可供C/C复合材料使用的无损检测技术.     

扫描电镜及X射线能谱仪在首饰镀层检测中的应用

采用扫描电镜及X射线能谱仪对首饰镀层进行了检测,并对两种方法进行了比较.结果表明,镀铑首饰采用无损检测法较合适,而镀金首饰采用破坏性检测法较合适.     

公路桥梁无损检测技术应用分析

本文分析了我国公路桥梁现状及存在问题,阐述了对桥梁结构进行病害和损伤检测的必要性,重点介绍了回声波检测法、探地雷达检测法、射线探伤法等几种无损检测技术,以及无损检测技术在桥梁工程中的应用,供大家参考。     

Methodology for Mapping the Residual Stress Field in Serviced Rails Using LCR Waves

Thermal barrier coatings (TBCs), as effective thermal protection separating the substrate from high-temperature combustion gases and reducing the substrate temperature, are widely used in aerospace and other fields. During the service cycle of life, surface crack defects, interface disbond defects, and coating thickness changes are the main non-destructive testing (NDT) objects of TBCs. In this paper, the main active infrared thermography NDT techniques including the optical infrared thermography testing, the ultrasonic infrared thermography testing, and the microwave thermography testing techniques are reviewed. Through the summary and highlight of the detection principle and application status of these state-of-the-art techniques, the development of the active infrared thermography DNT technique in TBCs is presented. By comparing the sensitivity, advantages, and disadvantages of the techniques in TBC NDT, can provide a significant reference for researchers to choose an appropriate method. It is noteworthy that fabrication techniques of artificial defects for calibration of the active infrared thermography NDT technique inspection of TBC systems are also reviewed. Moreover, future trends in NDT for the TBC system based on the active infrared thermography NDT technique are also discussed and analyzed.

     

Additive manufacturing process monitoring and control by non-destructive testing techniques: challenges and in-process monitoring

This paper examines on the obstacles specific to the implementation of non-destructive testing (NDT) techniques in additive manufacturing (AM). The general challenges impeding the adoption of AM for volume production of parts, and the use of NDT techniques to ameliorate some of these challenges are studied. These challenges include the lack of understanding of AM materials, and insufficient standards for the mechanical testing and NDT of additively manufactured parts. An overview on the principle of operation for in-process inspection NDT methods is presented. The techniques include thermography, and acoustic emission testing. The applications of these NDT techniques in AM and their suitability for defects detection of additively manufactured parts are reviewed. The sensitivity, and the advantages and disadvantages of each technique are evaluated. The types of defects, and the detectability of these defects by NDT techniques are assessed.     

Detecting Damage in Composite Material Using Nonlinear Elastic Wave Spectroscopy Methods

Modern aerospace structures make increasing use of fibre reinforced plastic composites, due to their high specific mechanical properties. However, due to their brittleness, low velocity impact can cause delaminations beneath the surface, while the surface may appear to be undamaged upon visual inspection. Such damage is called barely visible impact damage (BVID). Such internal damages lead to significant reduction in local strengths and ultimately could lead to catastrophic failures. It is therefore important to detect and monitor damages in high loaded composite components to receive an early warning for a well timed maintenance of the aircraft. Non-linear ultrasonic spectroscopy methods are promising damage detection and material characterization tools. In this paper, two different non-linear elastic wave spectroscopy (NEWS) methods are presented: single mode nonlinear resonance ultrasound (NRUS) and nonlinear wave modulation technique (NWMS). The NEWS methods were applied to detect delamination damage due to low velocity impact (<12 J) on various composite plates. The results showed that the proposed methodology appear to be highly sensitive to the presence of damage with very promising future NDT and structural health monitoring applications.     

可视化无损检测技术研究进展

随着工业产品质量及服役安全验证要求的不断提升,常规无损检测已无法满足实时、在线、快速作业的需要,可视化无损检测技术应运而生。将可视化技术应用于产品质量检测与评估,具有清晰、直观、精准等优点,对提高产品检测效率和精度,实现大规模工业化、信息化、智能化检测具有重要意义。主要从超声无损检测及成像技术、红外热波无损检测及其图像序列处理技术、电磁无损检测及其信号采集处理技术、层析成像技术与三维重构方法,以及可视化无损自动检测技术等方面,介绍了国内外可视化无损检测技术的研究进展,分析了各类检测技术的适用范围和特点,并对其发展方向和应用前景进行了展望。     

Friction stir welding of high-strength aerospace aluminum alloy and application in rocket tank manufacturing

Friction stir welding (FSW) has been widely adopted in aerospace industry for fabricating high-strength aluminum alloy structures, such as large volume fuel tanks, due to its exceptional advantages including low distortion, less defects and high mechanical properties of the joint. This article systematically reviews the key technical issues in producing large capacity aluminum alloy fuel tanks by using FSW, including tool design, FSW process optimization, nondestructive testing (NDT) techniques and defect repairing techniques, etc. To fulfill the requirements of Chinese aerospace industry, constant-force FSW, retractable tool FSW, lock joint FSW, on-line NDT and solid-state equal-strength FSW techniques, as well as a complete set of aerospace aluminum FSW equipment, have been successfully developed. All these techniques have been engineered and validated in rocket tanks, which enormously improved the fabrication ability of Chinese aerospace industry.     

Applications of non-destructive testing techniques for post-process control of additively manufactured parts

This paper presents an overview on the principle of operation for post-process inspection non-destructive testing (NDT) techniques. The techniques include visual inspection, liquid penetrant testing, magnetic particle testing, eddy current testing, ultrasonic testing, and radiography. The applications of these NDT techniques in additive manufacturing (AM) and their suitability for defects detection of additively manufactured parts are reviewed. The sensitivity, and the advantages and disadvantages of each technique are evaluated. The types of defect, and the detectability of these defects by NDT techniques are assessed. The applicability of each NDT technique for different categories of AM process is discussed. The categories of AM are, namely, material extrusion, powder bed fusion, vat photopolymerisation, material jetting, binder jetting, sheet lamination, and directed energy deposition.     

Recommended NDT Practice and its Model-based Investigation for Eddy Current Inspection of Aerospace Structures

This paper describes a model-based investigation of inspection standards being developed as a recommended practice for eddy current (EC) NDT of aerospace structures for surface cracks. Compared to experimental investigations that can be laborious and expensive, model-based approach provides cost-effective and quantitative verifications of the recommended practice that covers wide ranges of materials, probes, instruments, frequencies, and test conditions. Probe signals for a number of specified standard notches are predicted and the expected amplitudes and phase-angle ranges are determined for various test conditions, in order to examine the influence of material electrical conductivity, frequency, and probe types. For a few selected situations, the model predictions are validated against experimental data. This study verifies the adequacies of the recommended specifications, especially of the reference notch selections and their response amplitudes for various test conditions, as well as confirming the suitability of using vertical amplitude alone for all the test situations. The influence of probe cable and the issue of three-point calibration are also discussed specifically in this investigation.     

核结构材料焊接中的无损检测技术

在核工业领域，对一些焊接结构件，必须把焊接缺陷控制在工程设计要求的水平。无损检测技术能够较为方便地识别焊接缺陷。本文重点介绍了渗透检测技术、氦质谱真空检测技术、射线探测技术和残余应力测试等几种无损检测技术，并对无损检测技术在核结构材料焊接中的应用及展望提了几点看法。