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陶瓷薄膜的制备技术多种多样,如物理气相沉积、化学气相沉积、高温烧结和"溶胶-凝胶"法等.这些技术对制备条件都有较高的要求:如高温高真空等.近年发展起来的在低温条件下沉积陶瓷薄膜的技术为我们提供了一种设备简单,在接近室温、常压下可进行操作的方法.本文就这一新兴工艺及其机理进行了评述. 相似文献
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低温多晶硅薄膜晶体管(LTPS-TFT)驱动技术是实现大尺寸全彩平板显示的必由之路.然而,传统的低温多晶硅薄膜制作工艺存在着工序复杂、薄膜均匀性差、可能有金属污染且造价昂贵等问题.因此,有必要研发新一代的低温多晶硅薄膜制备工艺以期进一步提高薄膜质量,降低驱动成本.本文首先介绍了金属诱导横向晶化法(MILC)和准分子激光晶化法(ELA)制备低温多晶硅薄膜的原理,分析了两者各自的优缺点.接着,重点阐述了电感耦合等离子体化学气相沉积法(ICP-CVD)的工作原理和特点,并介绍了目前ICP-CVD在低温多晶硅薄膜制备上所取得的进展. 相似文献
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本文主要介绍了目前碳包覆纳米金属材料的主要合成途径及其形成机理,主要合成途径有:电弧放电法、化学气相沉积法、高温热解法、低温热解法、聚能法、爆炸法、机械球磨法等。根据合成工艺,总结阐述了碳包金属材料在电磁性存储、微电子技术、生物医学、催化材料、光电辐射技术等不同领域的应用。 相似文献
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激光化学气相沉积(LCVD)是八十年代才兴起的表面镀膜技术,它将激光技术与化学气相沉积结合成一个整体,开拓了新的低温快速沉积领域。LCVD具有下述特点: 1)低温化。激光激活反应物分子,可在低温选定波长切断材料气体分子健,有选择地进行化学反应。为微电子器件提供了变革性工艺,扩大了CVD的应用范围。2)节能化。通常化学反应中,粒子与粒子间进行无规则的碰撞,只有那些能量超 相似文献
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纵观金属表面改性的历史,陶瓷被覆改善金属表面的性质并不是全新的技术。例如:采用高温烧成法的玻璃型陶瓷覆面以及金属陶瓷覆面技术很早就实用化了。近年来开发了化学气相沉积法(CVD)、物理气相沉积法(PVD)、等离子喷镀法、爆炸喷镀法和低温烧成法等陶瓷覆面技术,制成了从数微米到数百微米的覆膜。而且除了采用一般的氧化物陶瓷外,也采用了氮化物、碳化物、硼化物和硅化物等超硬质陶瓷进行覆面。日本东芝公司以美国Kaman Science公司的基本技术为基础,利用热化学反应,开发了在金属表面被覆以氧化铬为基体的复合陶瓷层的新技术——TOSRIC技术,被覆层粘合强度高、无气孔且硬度高。 1.TOSRIC技术及类型陶瓷覆面的方法很多(图1)。TOSRIC 相似文献
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低压冷喷涂铝涂层微观结构与沉积特性研究 总被引:1,自引:0,他引:1
低压冷喷涂技术是一种不同于高压冷喷涂技术的新型喷涂工艺。本文以体积比为3:7的氧化铝粉末和铝粉的混合粉末为原料,以压缩空气为工作气体,利用低压冷喷涂设备在Q235钢基体上制备Al涂层,研究了温度、喷距、送粉速率和喷嘴横向移动速度等工艺参数对涂层沉积效率的影响。采用光学显微镜、扫描电镜,研究了涂层的微观结构和沉积特性。实验结果表明:在工作气体压力保持0.6 MPa不变的情况下,温度400℃、喷距25 mm、送粉速率为30—40 g/min、喷嘴横向移动速度4.0 m/min时,铝涂层沉积效率最佳;同时Al2O3陶瓷相的加入有利于涂层的沉积。 相似文献
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一般致密SiC材料的制备需要极高的温度,而降低制备温度一直是SiC制备领域的重要研究方向。采用流化床化学气相沉积法,在球形二氧化锆陶瓷颗粒上制备了厚度为几十微米的SiC包覆层。通过对不同温度SiC包覆层的显微形貌及微观结构变化规律研究,给出了沉积效率变化规律,发现低温产物富硅,而高温产物富碳。对不同氩气含量的实验研究发现,氩气的加入可以促进沉积反应向富碳方向移动,从而可以在显著降低温度的条件下制备出致密SiC包覆层。综合实验结果给出了流化床化学气相沉积方法在不同温度及氩气浓度条件下制备SiC的物相分布图。 相似文献
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Low temperature deposition (LTD) is an actual frontier in materials sicence and engineering, especially for thin film technology In this paper the fundamentals and processing of lew temperature deposition of TiN coating are reviewed. The prerequisites of a law temperature deposition process are enough good densification, hardness and adhesion of the deposited coating. The fundamentals Of low temperature deposition are Structure zone model and nonequilibrium plasma vapor growth in a combined DC and pulsed electromagnetic fields. namely a combination of a DC bias voltage superimposed by a DC pulsed bias voltage with variable frequency and peak voltage height. Low temperature deposition processing can be realized simply with only stationary eledric fields. However, sensitivity of the product quality to the process parameters is the main barrier of this processing in the way to mass production. Low temperature deposition processing using the effects of a combined DC and pulsed electromagnetic fields has attained some promising results for the future commercialization. But they need Still further Systematic and deep study The application of low temperature deposition processing is nOt limited in range of low melting substrate materials. It is also important for internal stress control, defect minimization, microstructure densification and pedermance improvement for coatings on broad spectrum of substrate materials as well as for different types of applications. 相似文献
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耐高温涂层及其性能表征的研究进展 总被引:3,自引:1,他引:2
耐高温涂层在涡轮喷气发动机、高温轴承、高超声速飞行器的热防护以及切削刀具等领域具有广阔的应用背景,在技术创新层面,也具有很大的潜力和良好的发展前景。首先综述了现有耐高温涂层的研究进展,主要包括扩散涂层和覆盖涂层两大类和陶瓷涂层等七小类,并进行了分类讨论。在此基础上探讨了各种耐高温涂层的制备方法和技术手段,归类总结了耐高温涂层性能的主要表征方法,综述了耐高温涂层的耐高温及失效机理,最后展望了其发展的方向。随着相关研究的深入,耐高温涂层在耐温性、抗氧化性、蠕变性、抗冲蚀性等基本性能方面得到进一步提升,同时对其力学性能、鲁棒性能等方面又提出了更高要求。 相似文献
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The results and development of a new full ceramic abradable turbine seal coating material prepared by thermal spraying are presented. The main objective was to achieve high temperature abradability and low mating part wear using an erosion-resistant coating with high temperature stability and thermal shock resistance. The new coating was successfully laboratory tested at temperatures of at least 1100°C (2012°F). Commercial metal-based abradable coatings which are currently available are limited to lower operating temperatures. Typical plasma- sprayed ceramic coatings, because of inherent high particle velocities, are normally to dense to permit abrading without experiencing high turbine blade tip wear damage. In contrast, lower velocity combustion-sprayed ceramic coatings frequently have lower toughness and cohesive particle strength for resistance to abrasive erosion. The new coating material is designed to react exothermically, during combustion spraying, to produce a coating both with high interparticle cohesive strength for resistance to abrasive particle erosion and with controlled porosity for low turbine blade tip wear and effective abradability. Adjustment of spraying conditions gives flexibility to alter the coating hardness and porosity and permits the tailoring of abradability and erosion resistance properties for specific operating requirements.Based on specially developed test methods for high temperature abradability, high temperature particle erosion and thermal cycling, the modified zirconia coating showed superior performance to high performance baseline materials tested in the program. Industrial evaluation of this coating is presently being conducted. 相似文献
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Rajesh P Muraleedharan CV Komath M Varma H 《Journal of materials science. Materials in medicine》2011,22(3):497-505
Pulsed laser deposition (PLD) has been used to deposit hydroxyapatite (HA) ceramic over titanium substrate with an interlayer
of titania. PLD has been identified as a potential candidate for bioceramic coatings over metallic substrates to be used as
orthopedic and dental implants because of better process control and preservation of phase identity of the coating component.
However, direct deposition of hydroxyapatite on titanium at elevated temperature results in the formation of natural oxide
layer along with some perovskites like calcium titanate at the interface. This leads to easy debonding of ceramic layer from
the metal and thereby affecting the adhesion strength. In the present study, adherent and stable HA coating over Ti6Al4V was
achieved with the help of an interlayer of titania. The interlayer was made to a submicron level and HA was deposited consecutively
to a thickness of around one micron by exposing to laser ablation at a substrate temperature of 400°C. The deposited phase
was identified to be phase pure HA by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and
inductively coupled plasma spectrometry. The mechanical behavior of coating evaluated by scratch test indicates that the adhesion
strength of HA coating was improved with the presence of titania interlayer. 相似文献
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消失模铸造镁合金表面陶瓷化研究 总被引:3,自引:0,他引:3
利用消失模铸造工艺,以PbO-ZnO系低温玻璃粉作为主要的陶瓷化材料,进行了镁合金表面陶瓷化研究。利用SEM、XRD、线能谱分析和极化曲线等手段研究了镁合金表面陶瓷涂层的组织结构、相组成和元素的分布,测试了陶瓷层的耐腐蚀性能。结果表明,在基体的表面形成厚度为40~80μm左右的陶瓷涂层,涂层的主要成分有低温玻璃粉组成,并且成分组成由表层到基体变化明显,与基体之间形成了良好的结合界面。通过电化学性能测试表明,表面陶瓷层的腐蚀电位大幅度的提高,腐蚀电流密度降低,经过表面陶瓷化的镁合金耐腐蚀性能得到了提高。 相似文献