共查询到19条相似文献,搜索用时 140 毫秒
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为了满足高温环境下的压力测量需求,研制了一种基于CO2激光焊接的高温F-P光纤压力传感器.介绍了MEMS压力敏感结构的制作过程,分析了传感器各组件之间的焊接工艺,实现了高温F-P光纤压力传感器的无胶化封装.在此基础上,对传感器的温度特性和高温压力性能进行了研究.结果表明,采用CO2激光焊接封装的传感器可靠性高,在高温下... 相似文献
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为了满足高温环境下的压力测量需求,研制了一种基于CO2激光焊接的高温F-P光纤压力传感器。介绍了MEMS压力敏感结构的制作过程,研究了传感器各组件之间的焊接工艺,实现了高温F-P光纤压力传感器的无胶化封装。在此基础上,对传感器的温度特性和高温压力性能进行了研究。结果表明,采用CO2激光焊接封装的传感器可靠性高,在高温下信号传输正常,未出现光谱能量衰减现象。在300 ℃高温下,传感器在0~2.5 MPa范围内的测量误差小于0.2 %FS,能够实现高温压力的准确测量。但温度对传感器的影响不可忽略,在实际应用过程中需对传感器进行温度补偿。 相似文献
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半导体碳化硅由于具有宽的带隙,高的导热系数以及大的电子迁移率等优点,使其成为一种在高温、高频、大功率电子器件中具有应用前景的材料。碳化硅器件的性能受表面和界面质量的影响。在高温条件下退火碳化硅表面的重构,形貌也会发生变化,导致与金属或其他材料接触的表面结构不同。因此,碳化硅器件会受到表面重构和形貌的影响。扫描隧道显微镜/扫描隧道谱(STM/STS)是一种可以在实空间获得表面重构的形貌信息以及电子结构非常有用的工具。这篇综述介绍了用STM/STS分析了4H(6H)-SiC的各种表面重构及其电子结构,旨在促进表面科学和碳化硅生长以及器件的发展和进步。 相似文献
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很少材料具有和碳化硅(SiC)一样卓越的综合性能。在物理性质方面,碳化硅具有几乎和金刚石一样的极高硬度,它能耐1000℃以上的温度,在这样的高温下不发生明显变化。作为半导体,和硅一样,碳化硅具有许多优良特性,适合用于在高温和高频条件下工作及在辐射环境中工作的电子器件。它还有透明性,刚性和强度极高的特点。由于具有这样一些引人注目的特性,SiC一直是由研磨材料到高温器件的各种传统与精密用途的首选材料。 相似文献
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碳化硅陶瓷基复合材料以其高比强度、高比模量、高导热、良好的耐烧蚀性能、高温抗氧化性、抗热震性能等特性,广泛应用于航空航天、摩擦制动、核聚变等领域,成为先进的高温结构及功能材料。本文综述了高导热碳化硅陶瓷基复合材料制备及性能等方面的最新研究进展。引入高导热相,如金刚石粉、中间相沥青基碳纤维等用以增强热输运能力;优化热解炭炭与碳化硅基体界面用以降低界面热阻;热处理用以获得结晶度更高、导热性能更好的碳化硅基体;设计预制体结构用以建立连续导热通路等方法,提高碳化硅陶瓷基复合材料的热导率。此外,本文展望了高导热碳化硅陶瓷基复合材料后续研究方向,即综合考虑影响碳化硅陶瓷基复合材料性能要素,优化探索高效、低成本的制备工艺;深入分析高导热碳化硅陶瓷基复合材料导热机理,灵活运用复合材料结构与性能的构效关系,以期制备尺寸稳定、具有优异热物理性能的各向同性高导热碳化硅陶瓷基复合材料。 相似文献
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碳化硅高技术陶瓷及其应用 总被引:1,自引:0,他引:1
碳化硅高技术陶瓷以其耐磨性、耐高温性、耐腐蚀性尤为突出,已广泛应用于机械、汽车、宇航、化工、石油等许多工业领域。本文介绍了碳化硅陶瓷作为结构材料的应用如密封环、研磨介质、防弹板、研磨盘、高温耐蚀部件等:同时从碳化硅陶瓷的市场价值出发介绍了碳化硅陶瓷作为工程材料的应用。 相似文献
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连续SiC纤维最主要的制备方法是先驱体转化法, 目前已发展到第三代, 它主要作为SiC基复合材料(SiCf/SiC)的增强体。SiCf/SiC具有优异的耐高温、抗氧化和高温抗蠕变性, 及其在中子辐照条件下的低放射性, 成为高温、辐射等苛刻条件下结构部件的优先候选材料。本文首先对国内外SiC纤维的发展, 尤其是对第三代SiC纤维的不同制备思路和特征进行了介绍。然后, 对SiCf/SiC制备工艺和性能的进展进行了综述, 突出了制备工艺创新与SiC纤维发展的关系。最后, 对近几年SiCf/SiC在高性能航空发动机、聚变反应堆领域的应用进展进行了总结, 并对国内连续SiC纤维和SiCf/SiC复合材料的发展进行了展望。 相似文献
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Robust Free‐Standing Nano‐Thin SiC Membranes Enable Direct Photolithography for MEMS Sensing Applications
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Hoang‐Phuong Phan Tuan‐Khoa Nguyen Toan Dinh Alan Iacopi Leonie Hold Muhammad J. A. Shiddiky Dzung Viet Dao Nam‐Trung Nguyen 《Advanced Engineering Materials》2018,20(1)
This work presents fabrication of micro structures on sub–100 nm SiC membranes with a large aspect ratio up to 1:3200. Unlike conventional processes, this approach starts with Si wet etching to form suspended SiC membranes, followed by micro‐machined processes to pattern free‐standing microstructures such as cantilevers and micro bridges. This technique eliminates the sticking or the under‐etching effects on free‐standing structures, enhancing mechanical performance which is favorable for MEMS applications. In addition, post‐Si‐etching photography also enables the formation of metal electrodes on free standing SiC membranes to develop electrically‐measurable devices. To proof this concept, the authors demonstrate a SiC pressure sensor by applying lithography and plasma etching on released ultrathin SiC films. The sensors exhibit excellent linear response to the applied pressure, as well as good repeatability. The proposed method opens a pathway for the development of self‐sensing free‐standing SiC sensors. 相似文献
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Ju-Hyeon Yu Hirotatsu Kishimoto Naofumi Nakazato Joon-Soo Park Akira Kohyama 《Advanced Composite Materials》2018,27(5):531-539
SiC fiber-reinforced SiC matrix (SiC/SiC) composites are expected as a high-temperature structural material for the application of aerospace and nuclear energy system due to their high-temperature stability, reduced-activation property, and excellent irradiation resistance. It was investigated the size effects of test specimen on the fracture behaviour and apparent strength of SiC/SiC tubes in order to minimize the size of test specimen, as well as to develop circumferential tensile test method for SiC/SiC fuel cladding of nuclear reactor. The tube specimens with a narrow width (less than 5 mm) represented the stable value of apparent strength. In case of wide width (>5 mm), the apparent strength of test specimen decreased with the increase in specimen width. It was observed that the fracture of the test specimen with wide width was initiated from the sides of test specimen due to the local contact between loading pin and the test specimen. It is required to use the material with high modulus as a loading pin material in order to avoid the stress concentration caused by local contact. 相似文献
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A 248-nm, 23-ns pulsed excimer laser was used to micromachine 50 μm thick diaphragms in 6H–SiC wafers. The diaphragms were then subjected to high-pressure (0.7–7 MPa) and high temperature (500 K) tests to obtain the pressure-deflection curves. A finite element model was used to predict the stresses and displacements as a function of temperature and pressure. Model data is in good agreement with experiments. The stresses, strains and displacements were determined in order to facilitate the design of high-temperature micro-electro-mechanical-system pressure sensors. 相似文献
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连续碳纤维增强碳化硅(Cf/SiC)复合材料以其耐高温、高强度、低密度等特性已成为新一代航空发动机高温部件的首选材料。采用聚合物浸渍裂解法(PIP)成功制备出适用于航空发动机高温部件的Cf/SiC复合材料,其密度为1.83g/cm3。在发动机典型工作温度1200℃条件下,通过本工艺制备Cf/SiC材料的弯曲强度高达712MPa,略高于材料的室温弯曲强度(641MPa)。这一现象可能由碳纤维在冷却过程中产生的残余应力引起。此外,在温度为1200℃、加载压力120MPa的条件下,材料的稳态高温蠕变速率为2.08×10-3%/h,基体开裂和界面滑动可能是材料宏观变形的主要原因。 相似文献
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T. Ishikawa 《Advanced Engineering Materials》1999,1(1):59-61
Low fracture resistance is one of the most serious limitations of ceramic materials. The new SiC fiber-bonded ceramic presented here was developed to address this problem. The thermally conductive material is a candidate for such demanding applications as gas turbine engine hot section components, where its high-temperature capability, high thermal conductivity, and low density make it very attractive for replacement of heavy metal super alloy components. Synthesized by hot-pressing the material with the commercial name Sintered Tyrannohex consists of hexagonal columnar SiC fibers with a thin interfacial carbon layer between them. 相似文献
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针对高超声速飞行器新型超高温结构力/热/氧化关键性能参量试验测试的迫切需求,自行设计并建立了可实现在高达1 500℃极端高温氧化环境下进行结构断裂性能测试的辐射式热/力联合试验系统,并对耐高温C/SiC复合材料结构在1 500℃等高温氧化环境下的断裂强度以及出现断裂时的时间点等关键性能参数进行了试验测试,当试验温度从1 000℃上升至1 500℃,C/SiC复合材料试验件的断裂强度下降了47.5%,断裂时间缩短50.1%。本极端高温载荷试验系统为高超声速飞行器结构热强度研究提供了重要的氧化环境下的热/力联合试验测试手段。研究结果表明:通过高温预加载可以明显提高C/SiC复合材料结构的断裂强度,增幅为38%,承载时间提高61.1%。试验结果为高超声速飞行器复合材料部件在极端热环境下的安全可靠性设计以及强度性能的改进提供了重要依据。 相似文献
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J. -P. Cottu J. -J. Couderc B. Viguier L. Bernard 《Journal of Materials Science》1992,27(11):3068-3074
The influence of fibre reinforcement (10 vol % SiC fibres) on the precipitation and hardening behaviour of a metal matrix composite was studied using microhardness tests and transmission electron microscopy observations. It was shown that the hardening kinetics is enhanced by the SiC reinforcement due to the fact that precipitation preferentially develops on dislocation lines. Moreover, the high-temperature deformation strongly increases the precipitation rate as the material is reinforced. 相似文献