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本文综述了利用等离子技术喷涂高性能陶瓷涂层的技术特点和应用情况以及几种热点陶瓷涂层的特性,指出了等离子技术喷涂陶瓷涂层中存在的问题,分析了可行的解决方法。 相似文献
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水稳等离子喷涂是占据重要地位的气稳等离子喷涂的另一种选择,它具有功率大,成本低,喷涂速度高等突出的优点,在热喷涂技术向大产值和大批量迈进的形势下,这项技术开始受到更多的重视和应用。北京廊桥表面技术有限公司贾鹏先生在本文中从水稳等离子喷涂的工作原理及其特点、应用方面等了详尽的阐述。 相似文献
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超音速等离子喷涂技术由于具有高温、高速的独特优点,且制备的陶瓷涂层结合强度和致密度高,孔隙率低,具有优良的耐磨损、耐腐蚀、抗氧化和热冲击性能,已成为一些发达国家竞相研究的热点.本文介绍了常用的陶瓷涂层材料,综述了超音速等离子喷涂技术及其制备陶瓷涂层的工艺特点,并对超音速等离子喷涂制备高性能陶瓷涂层的发展趋势进行了展望. 相似文献
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等离子喷涂技术的新进展 总被引:1,自引:0,他引:1
近年来等离子喷涂设备在自动控制和硬件装备上取得了显著的进步,从而带动了涂层的开发和应用新发展,本文简要介绍了近十搂一在等离子喷涂装备和功能方面的新进展。列举了涂层应用的实例,着重介绍了等离子涂层在内燃机上的应用。 相似文献
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结合汽车耐损、腐蚀和表面抗氧化要求,对采用等离子喷涂涂层进行修复再制造和强化的汽车部位的实践进行了总结。重点介绍等离子喷涂技术在汽车发动机上的实践应用,并针对汽车零部件等离子喷涂涂层应用现状提出了相应改进方法。 相似文献
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《Ceramics International》2017,43(13):9715-9722
In the present study, hydroxyapatite (HAp) coatings were deposited on Ti-6Al-4V alloy by solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) processes and the properties of the coatings were compared. The feedstock powder for SPS method was prepared by coprecipitation technique and characterized for phase and morphology. The obtained HAp coatings were characterized by X-ray diffractometry, Raman spectroscopy and FT-IR spectroscopy. The biocompatibility of the coatings was evaluated using osteoblast like cells. Both the SPS and SPPS hydroxyapatite coatings exhibited similar crystallinity. Interestingly, the HAp-SPS coating showed marginally higher biocompatibility compared to HAp-SPPS and control samples. The wear and corrosion behavior of these coatings was also studied in Hanks' medium. The hydroxyapatite coating fabricated from SPS technique exhibited better corrosion and wear resistance compared to SPPS coating. 相似文献
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Xinzhang Zhou Vijay Shukla W. Roger Cannon Bernard H. Kear 《Journal of the American Ceramic Society》2003,86(8):1415-1420
Rapidly solidified ZrO2 (Y2 O3 )–Al2 O3 powders were prepared by melting fine-particle aggregates in a high-enthalpy plasma flame and then rapidly quenching them in cold water or on a copper chill plate. To ensure complete melting and homogenization of all the particles before quenching, the water-quenching treatment was often repeated two or even three times. The resulting melt-quenched powders and splats displayed a variety of metastable structures, depending on composition and cooling rate. ZrO2 -rich material developed an extended solid solution phase, whereas eutectic material formed a nanofibrous or amorphous structure. Under high cooling rate conditions, the ZrO2 -rich material developed a nanocomposite structure ( t -ZrO2 +α-Al2 O) directly by melt-quenching, whereas, more typically, such a structure was developed only after postannealing of the as-quenched metastable material. 相似文献
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The low bonding strength between hydroxyapatite (HA) and the metal substrate interface of plasma-sprayed HA coating has been a point of potential weakness in its application as a biomedical prosthesis. In the present study, yttria-stabilized (8 wt%) zirconia (YSZ) has been used to enhance the mechanical properties of HA coatings. The effects of YSZ additions (in the range 10–50 wt%) on the phase composition, microstructure, bond strength, elastic modulus, and fracture toughness of plasma-sprayed HA/YSZ composite coatings have been studied. The results indicated that decomposition of HA during plasma spraying was reduced significantly with the addition of zirconia. The higher the zirconia content, the lower the amount of calcium oxide, tricalcium phosphate, and tetracalcium phosphate formed in the coatings. In addition, there was a trace of calcium zirconate formed when less than 30 wt% zirconia was present. A solid solution of HA mixed with YSZ formed during plasma spraying; however, the amount of unmelted particles increased as the zirconia increased. The mechanical properties of the HA/YSZ composite coatings, such as bond strength, elastic modulus, and fracture toughness, increased significantly as the contents of zirconia increased. 相似文献
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Rodney W. Trice David W. Prine K. T. Faber 《Journal of the American Ceramic Society》2000,83(12):3057-3064
Cylindrical, stand-alone tubes of plasma-sprayed alumina were tested in compression in the axial direction at room temperature, using strain gauges to monitor axial and circumferential strains. The primary compression-loading profile used was cyclic loading, with monotonically increased peak stresses. Hysteresis was observed in the stress–strain response on unloading, beginning at a peak stress of 50 MPa. The modulus decreased as the maximum applied stress increased. The stress–strain response was only linear at low stresses; the degree of nonlinearity at high stresses scaled with the stress applied. One-hour dwells at constant stress at room temperature revealed a time-dependent strain response. Using transmission electron microscopy and acoustic emission to investigate deformation mechanisms, the stress–strain response was correlated with crack pop-in, growth, and arrest. It is proposed that the numerous defects in plasma-sprayed coatings, including porosity and microcracks, serve as sites for crack nucleation and/or propagation. As these small, nucleated cracks extend under the applied stress, they propagate nearly parallel to the loading direction along interlamellae boundaries. With increasing stress, these cracks ultimately link, resulting in catastrophic failure. 相似文献
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《Ceramics International》2016,42(13):14299-14312
As one of the promising methods that can be employed to fabricate high-performance thermal barrier coatings (TBCs), suspension plasma spraying (SPS) or solution precursor plasma spraying (SPPS) has received significant attention in academic research. Enhanced performances have been shown in the SPS-/SPPS-coatings due to their special microstructures, such as uniformly distributed micro-pores, vertical cracks or columnar structures. Since there are more complexities than conventional plasma spraying methods, many works have been devoted to study the mechanism and properties of SPS-/SPPS-coatings during the past decades. In this work, the latest development of SPS or SPPS is reviewed in order to discuss some key issues in terms of preparation of suspension or solution precursor, injection mode of liquid phase, interaction between liquid and plasma jet, microstructure of as-sprayed coatings and corresponding deposition mechanism. Meanwhile, the potential application of SPS or SPPS in some new-type TBCs is introduced at the end of this paper. 相似文献
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Pavel Ctibor Jakub Čížek Josef Sedláček František Lukáč 《Journal of the American Ceramic Society》2017,100(7):2972-2983
Positron annihilation spectroscopy was employed for investigation of vacancy‐like defects in plasma‐sprayed barium titanate. Defect studies were combined with measurement of dielectric properties of barium titanate coatings. Samples prepared by gas‐stabilized plasma spray (GSP) torch and by plasma torch with the hybrid water‐argon stabilization (WSP‐H) were studied. Processing parameters were selected so that GSP coatings were sprayed in reductive conditions, whereas WSP‐H coatings were prepared in oxidizing environment. As‐sprayed GSP coating is dark, whereas WSP‐H one is light. The dielectric properties of WSP‐H coating are superior to those for GSP one. Defect studies revealed that both GSP and WSP‐H coatings contain titanium vacancies. However, GSP coating contains in addition a considerable concentration of oxygen vacancies. Some fraction of oxygen vacancies in GSP coating is coupled with titanium vacancies forming partial Schottky defect. The structure of WSP‐H coating is less disordered and contains only a low concentration of oxygen vacancies. This is consistent with reductive and oxidizing conditions in GSP and WSP‐H spraying, respectively. Annealing at elevated temperatures in air leads to removal of oxygen vacancies which are filled by oxygen diffusing into the samples. 相似文献
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Role of Lamellae Morphology on the Microstructural Development and Mechanical Properties of Small-Particle Plasma-Sprayed Alumina 总被引:1,自引:0,他引:1
The influence of spray parameters on the microstructure and flexural strength of plasma-sprayed alumina was investigated. Coatings were applied using a small-particle plasma spray (SPPS) method, which is a recently patented process that allows submicrometer-sized powders to be sprayed. Using identical starting powders, coatings that were produced using two distinctly different spray conditions exhibited significant differences in both microstructure and strength. Scanning electron microscopy investigations of single lamellae (or splats) revealed that, for one spray condition, melted alumina particles will splash when they contact the substrate. The morphology of the splats that comprised the subsequent layers of the coating also were highly fragmented and thinner than lamellae formed under "nonsplashing" spray conditions. The surface roughness was strongly dependent on the morphology of the lamellae; increased roughness was noted for fragmented splats. Thick coatings that were comprised of splashed splats developed a unique microstructural feature that was responsible for the observed increase in roughness. These microstructural differences greatly influenced the flexure strength, which varied from 75 ± 21 MPa for the nonsplashing spray condition to 17 ± 2.4 MPa for the "splashing" condition. 相似文献
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《Journal of the European Ceramic Society》2020,40(8):2731-2745
Thermal barrier coatings (TBCs) play a pivotal role in protecting the hot structures of modern turbine engines in aerospace as well as utility applications. To meet the increasing efficiency of gas turbine technology, worldwide research is focused on designing new architecture of TBCs. These TBCs are mainly fabricated by atmospheric plasma spraying (APS) as it is more economical over the electron beam physical vapor deposition (EB-PVD) technology. Notably, bi-layered, multi-layered and functionally graded TBC structures are recognized as favorable designs to obtain adequate coating performance and durability. In this regard, an attempt has been made in this article to highlight the structure, characteristics, limitations and future prospects of bi-layered, multi-layered and functionally graded TBC systems fabricated using plasma spraying and its allied techniques like suspension plasma spray (SPS), solution precursor plasma spray (SPPS) and plasma spray –physical vapor deposition (PS-PVD). 相似文献