航空发动机用热障涂层的发展

在延长航空发动机热端部件的寿命，提高效率，降低燃料消耗等方面，热障涂层已成为改善航空发动机性能的一种有效手段。随着等离子喷涂技术的不断完善，电子束蒸发物理气相沉积法，激光喷涂法等也相继问世。目前，对涂层剥落机理和寿命预测模型的研究了取得了相当大的进展，热障涂层的应用范围正不断扩大。     

电爆喷涂技术在材料表面制备涂层的研究进展

综述了电爆喷涂技术在材料表面制备涂层的研究进展和应用.给出了电爆喷涂技术的特点,喷涂设备的工作原理以及喷涂材料的种类;详细讨论了放电参数、喷涂材料与基体材料的几何尺寸、喷涂室气压、复合涂层等因素对涂层质量的影响;列举了电爆喷涂技术的实际应用;进一步分析了将来需要研究的问题.     

炭/炭复合材料表面等离子体喷涂羟基磷灰石涂层的生物学性能

采用等离子体喷涂法在炭/炭复合材料基体上制备了羟基磷灰石涂层,并对所制材料开展体外模拟和试验.结果表明:在体外模拟生理环境的Ringer溶液中,涂层组成相随浸泡时间发生变化.涂层表面有新生羟基磷灰石结晶析出并聚集长大.骨内种植试验期间,动物末出现排异和炎症反应,涂层与基体结合良好.组织学观察发现,涂层与骨界面处有明显的组织改建和新骨形成形态.炭/炭复合材料表面等离子体喷涂羟基磷灰石涂层作为一种潜在的骨组织修复材料具有良好的应用前景.     

等离子喷涂HA涂层的制备工艺优化与表征研究进展

从喷涂工艺的改进、涂层物相表征与性能检测、喷涂过程的数学模拟以及生物学评价等几个方面概述了近几年在生物医用材料表面等离子喷涂羟基磷灰石涂层的最新研究进展.并在分析评价的基础上展望了等离子喷涂法制备羟基磷灰石涂生物活性涂层的发展趋势.     

铝电解槽阴极TiB2涂层的研究进展

铝电解槽惰性阴极是近年来的研究热点，而TiB2因其优异的性能如电导率高、耐腐蚀性、与铝液良好的润湿性等而备受关注。综述了几种TiB2涂层的制备方法，重点介绍了溶胶涂敷法和等离子喷涂法在制备TiB2涂层方面的应用，并提出了制备方法中仍需要解决的问题。     

防钛火金属/陶瓷阻隔层设计与制备方法

金属/陶瓷阻隔层不仅可用于防钛火可磨耗封严涂层起阻燃作用,还可用于航空发动机热部件的热障涂层.以航空发动机压气机防钛火涂层的应用为主要背景,对金属/陶瓷阻隔层体系结构设计、涂层材料以及制备方法进行了系统的阐述.在涂层材料层面,分别介绍了陶瓷层与金属粘结层的材料成分设计、性能特点及其合成方法.在涂层制备技术层面,主要阐述了等离子喷涂(PS)、电子束物理气相沉积(EB-PVD)以及新型的等离子物理气相沉积(PS-PVD)3种方法.最后,面向防钛火涂层的发展需求,提出了金属/陶瓷阻隔层未来在材料升级、工艺优化、性能表征以及涂层技术理论体系等方面的发展方向.     

热喷涂陶瓷-树脂复合涂层的研究现状

陶瓷-树脂复合涂层兼具陶瓷材料和树脂材料的优异性能,具有良好的力学性能、摩擦磨损性能、耐腐蚀性能等,可用于防腐、减摩等领域,是当前热喷涂领域的新兴研究方向。如在先进航空发动机制造领域,通过在陶瓷涂层中添加树脂材料以增加涂层孔隙率,使高温可磨耗封严涂层的可磨耗性显著提升。然而,陶瓷与树脂的热物理性质和化学性质差异较大,导致复合涂层沉积时粒子的熔融沉积行为呈现复杂多样性,对涂层性能的影响规律尚不清晰。目前,国内外对陶瓷-树脂复合涂层的制备和应用开展了大量的研究,在不同热喷涂方法下,陶瓷材料和树脂材料对复合涂层结构、性能的影响取得了显著成果。基于此,本文综述了采用火焰喷涂、等离子喷涂、反应等离子喷涂三种热喷涂技术制备陶瓷-树脂复合涂层的国内外相关研究;比较分析了喷涂过程中,不同热喷涂技术对陶瓷材料与树脂材料的影响规律;梳理了等离子喷涂工艺的优化方法;展望了未来陶瓷-树脂复合涂层的研究重点与应用方向。     

等离子体预处理的炭/炭复合材料等离子喷涂制备羟基磷灰石涂层

为了提高等离子喷涂法所制羟基磷灰石涂层与炭/炭复合材料的结合力,采用氩气等离子体预处理结合等离子体喷涂法在炭/炭基体表面制备羟基磷灰石涂层,采用扫描电镜、X射线衍射仪、红外光谱仪、划痕仪等研究羟基磷灰石涂层的形貌、相组成以及羟基磷灰石涂层与基体的结合力。结果表明:采用或不采用等离子体处理炭/炭复合材料,羟基磷灰石涂层形貌和相组成接近,羟基磷灰石涂层的临界载荷分别为14.0 N、8.9 N,前者比后者临界载荷提高了57.3%。采用等离子体处理可提高等离子体喷涂羟基磷灰石涂层与炭/炭复合材料基体的结合力。     

热喷涂纳米涂层制备方法及材料的研究现状和展望

综述了热喷涂纳米涂层的制备方法现状及所用材料的发展情况，介绍了溶液等离子喷涂（SPS）、冷气动力喷涂（CGDS）、高速火焰喷涂（HVOF）技术制备纳米涂层的优势、纳米粉末材料的制备方法及发展趋势，指出纳米涂层制备的主要关键在于解决纳米粉末的输送技术和涂层制备过程中抑制纳米颗粒的长大趋势。纳米涂层的研究对推动热喷涂技术应用有着十分重要的作用。     

等离子喷涂法制备炭/炭复合材料硅酸钇涂层研究

采用等离子喷涂(Atmospheric plasma spraying,APS)法在炭/炭复合材料碳化硅(SiC)内涂层表面制备了硅酸钇涂层。分别采用XRD和SEM分析了所得涂层的微观结构,并测试了带有SiC/硅酸钇复合涂层的炭/炭复合材料试样在1500℃静态空气中的抗氧化性能。结果表明:通过调节喷涂粉料中的SiO2和Y2O3的摩尔比,可制得Y2SiO5、Y2Si2O7、Y2Si2O7/Y2SiO5和Y4Si3O12/Y2Si2O7/Y2SiO5四种不同结构的硅酸钇涂层;1500℃氧化73h后,SiC/Y4Si3O12/Y2Si2O7/Y2SiO5涂层试样的氧化失重速率相对较低,仅为1.01×10-4g.cm-.2h-1。     

Overview on the Development of Nanostructured Thermal Barrier Coatings

Thermal barrier coatings （TBCs） have successfully been used in gas turbine engines for increasing operation temperature and improving engine efficiency. Over the past thirty years, a variety of TBC materials and TBC deposition techniques have been developed. Recently, nanostructured TBCs emerge with the potential of commercial applications in various industries. In this paper, TBC materials and TBC deposition techniques such as air plasma spray （APS）, electron beam physical vapor deposition （EB-PVD）, laser assisted chemical vapor deposition （LACVD） are briefly reviewed. Nanostructured 7-8 wt pct yttria stabilized zirconia （7-8YSZ）TBC by air plasma spraying of powder and new TBC with novel structure deposited by solution precursor plasma spray （SPPS） are compared. Plasma spray conditions, coating forming mechanisms, microstructures,phase compositions, thermal conductivities, and thermal cycling lives of the APS nanostructured TBC and the SPPS nanostructured TBC are discussed. Research opportunities and challenges of nanostructured TBCs deposited by air plasma spray are prospected.     

Optical coatings for deuterium fluoride chemical laser systems

The high-power laser system has brought an interesting challenge to the development of optical coatings. A wide variety of coating specifications that are often contradictory have to be fulfilled. The choices of deposition process as well as coating materials are critical to coating loss, damage threshold, long-term stability, and other optical properties. A number of optical coatings being newly applied to deuterium fluoride laser systems are presented. The 3.8-mum laser reflection coatings with high damage threshold, multichromatic beam splitters, antireflection coatings with widely separated dual-wavelength bands, and 0.55-14-mum wide-band reflective coatings have been developed on substrates such as Si, Mo, fused silica, chemical vapor deposition ZnSe. Superior results have been obtained with ion-assisted deposition and electron-beam evaporation. Approaches to coating design and practical aspects of coating development are also discussed.     

磁控溅射沉积MCrAlY涂层技术研究

MCrA1Y（M=Fe，Ni，Co等）涂层是一种合金包覆涂层，用于防止燃气轮机涡轮部件的氧化和腐蚀。已经大规模用于沉积MCrA1Y涂层的技术有电子束物理气相沉积（EBPVD）、三极溅射、低压等离子喷涂（LPP）等。在一台专用装置上对磁控溅射沉积（MSD）MCrA1Y涂层进行了研究。结果表明MSDMCrA1Y涂层成分容易调整控制，涂层纯度高，涂层致密性和涂层厚度均匀性问题都比较容易解决；这些都比EBPVD或LPPS好。MSD的MCrA1Y涂层表面粗糙度远比LPPSMCrA1Y低。MSD的主要缺点是沉积速率低，但设备结构比较简单，制造工业规模的生产装置比较容易，可以弥补这个缺点。     

空心叶片内腔化学气相沉积设备及抗氧化涂层研究

由于高效气冷空心叶片内腔的结构越来越复杂,采用物理气相沉积(PVD)和等离子喷涂(PS)技术不能进行空心叶片内腔冷却通道的涂层防护,化学气相沉积可以进行冷却通道内表面抗氧化涂层的防护.通过CVD涂层设备的研制、涂层沉积工艺、高温涂层性能等研究,对内腔涂层的涂覆机理、工艺方法和内腔涂层的应用进行了讨论.结果表明:研制的CVD设备可靠、工艺参数稳定、内腔表面涂层涂覆达到100%,所研究的化学气相渗铝涂层具有优良的高温抗氧化性能,其在先进航空发动机高效气冷空心叶片内腔表面有很好的工程应用前景.     

热障陶瓷涂层的最新发展

综述了现代航空发动机用热障陶瓷涂层的最新发展，着重介绍了双陶瓷层，电子束物理气相沉积（EB－PVD）和溶液等离子喷涂（SPS）纳米热障陶瓷涂层的性能和特点。     

碳纳米洋葱制备方法的研究进展

碳纳米洋葱是继富勒烯与碳纳米管之后的又一新型碳纳米材料,在润滑剂、磁性材料等领域具有广阔的应用前景.综述了碳纳米洋葱的主要合成方法(电弧放电法、等离子体法、电子束照射法、热处理法、热解法和化学气相沉积法)及其特点,讨论了碳洋葱的形成机理,并简单介绍了碳纳米洋葱的性能及其应用.     

热喷涂及电子束物理气相沉积技术在热障涂层制备中的应用

对常用热障涂层制备技术,包括火焰喷涂、爆炸喷涂、大气等离子喷涂、高能等离子喷涂、超音速等离子喷涂、低压等离子喷涂、溶液注入等离子喷涂及电子束物理气相沉积技术进行了综述.介绍了上述几种制备技术的原理、工艺特点、存在不足及解决措施.认为发展爆炸喷涂工艺、溶液注入等离子喷涂工艺与EB-PVD工艺及其在新型热障涂层制备中的应用将是热障涂层制备技术研究的重点.     

Electron beam-induced formation of nanosized α-Fe crystals

Focused electron beam induced chemical vapor deposition was performed in a scanning electron microscope with a field emission gun using a precursor of iron carbonyl. Due to the longer deposition time and higher gas pressure than those of our previous electron beam-induced deposition method, a new type of deposition occurred. A large amount of nanosized crystals were produced around the focused beam irradiation point on a carbon substrate at room temperature. The nanocrystals were systematically characterized using transmission electron microscopy with electron energy loss spectroscopy (EELS), and were identified to be single crystals of α-Fe.     

Processes of the activated reactive evaporation type and their tribological applications

Plasma-assisted deposition processes have created a breakthrough in the deposition of compounds particularly the refractory compounds such as oxides, carbides, nitrides etc. Processes such as sputtering or ion plating inherently contain a plasma in the space between the target and the substrate. Evaporation and chemical vapor deposition processes have to be modified to include a plasma. In all of these reactive deposition processes the plasma plays a vital role in providing the activation energy necessary to carry out the process or to enhance its efficiency. All types of vapor sources can be used in these processes. The original development in 1971 used a thermionic electron beam evaporation source. Subsequently, resistance- heated, arc, induction, plasma electron beam and sputtering sources have all been used. In this paper we shall discuss the processes and the influence of deposition parameters on the microstructure and properties of compounds. Specific examples of the use of these compounds in tribological applications are considered.     

Carbon coatings on silica glass optical fibers studied by reflectance Fourier-transform infrared spectroscopy and focused ion beam scanning electron microscopy

Carbon coatings applied on optical fibers via chemical vapor deposition were characterized by a resistance technique, focused ion beam/scanning electron microscopy (FIB/SEM), and reflectance Fourier-transform infrared spectroscopy (FTIR). The resistance technique measures the thickness of carbon film by measuring the resistance over a section of optical fiber, and backing out the film thickness. The FIB/SEM system was used to remove a cross section of the optical fiber and carbon coating and using a scanning transmission electron detector the thickness was measured. The FTIR approach is based on the fact that the wavelength of the light in the mid-infrared region (~ 10 μm) is significantly larger than the typical thickness of the carbon coatings (< 0.1 μm) which makes the coating “semi-transparent” to the infrared light. Carbon coating deposition results in significant transformations of the band profiles of silica in the reflectance spectra that were found to correlate with the carbon coating thickness for films ranging from 0.7 nm to 54.6 nm. The observed transformations of the reflectance spectra were explained within the framework of Fresnel reflection of light from a dual-layer sample. The advantage of this approach is a much higher spatial resolution in comparison with many other known methods and can be performed more quickly than many direct measurement techniques.