氧气-乙炔火焰法在Al2O3陶瓷上沉积金刚石薄膜

用氧气－乙炔火焰法在氧化铝陶瓷片上沉积出了金刚石薄膜，并观察了薄膜的形貌结构及其在基片上的分布规律。对基片进行了适当的预处理，可以提高金刚石薄膜在基片上的成核密度。认为氧化铝陶瓷片与沉积金刚石薄膜之间易形成过渡层，初步探讨了在氧化铝陶瓷片上沉积金刚石薄膜的机理。     

金刚石薄膜在氧化铝陶瓷上低压成核

在微波等离子体化学气相沉积（MPCVD）系统中,用低压成核方法,在氧化铝陶瓷基片上获得了高成核密度的金刚石薄膜.实验表明,金刚石成核密度随系统压强减小而提高.在此基础上,提出一种MPCVD系统中金刚石成核的动力学模型,并指出对应于最高成核密度有一临界压强存在.     

燃焰法沉积金刚石薄膜的实验研究

研究分析了燃焰法沉积金刚石薄膜时基片表面处理状态，燃烧气体流量比基片温度对薄膜成核密度、质量和晶体形态的影响。结果表明，在不同粒度的研磨粉研磨的基片表面上金刚石薄膜成核密度不同；燃烧气体流量配比对金刚石薄膜的质量影响很大；基片温度是影响金刚石薄膜晶体形态的一个重要因素。     

系统压强对微波等离子体化学气相沉积金刚石成核的影响

为了在氧化铝上制备（100）定向织构的金刚石薄膜,必须先提高金刚石的成核密度,在微波等离子体化学气相沉积（MPCVD）系统中,采用低压成核的方法,在氧化铝陶瓷上沉积出高成核密度的金刚石薄膜,扫描电镜显示其成核密度可达10^8cm^-2。在此基础上,沉积出（100）织构的金刚石薄膜。     

陶瓷氧化铝—金刚石薄膜复合材料的研究

以有机高分子化合物酒精和氢气为反应气体,用热丝CVD法在Al2O3陶瓷基片上沉积出金刚石薄膜,用拉曼光谱,X射线衍射等方法进行了表征,探索了碳源浓度、热丝温度、基片温度和预处理工艺对金刚石薄膜结构和性能的影响。并且得到了最佳的工艺条件。探讨了金刚石在Al2O3衬底上的成核和生长机理。     

陶瓷氧化铝-金刚石薄膜复合材料的研究(英文)

以有机高分子化合物酒精和氢气为反应气体,用热丝 CVD法在 Al2O3陶瓷基片上沉积出 金刚石薄膜 ,用拉曼光谱, X射线衍射等方法进行了表征。探索了碳源浓度、热丝温度、基片温度 和预处理工艺对金刚石薄膜结构和性能的影响,并且得到了最佳的工艺条件。探讨了金刚石在 Al2O3衬底上的成核和生长机理。     

基片表面处理对金刚石成核密度影响的研究

为了研究基片的表面状态对金刚石成核密度的影响，采用了抛光清洁的基片、对样品划痕、基片加热脱附等不同的表面处理方法，对样品表面进行预处理，得到了不同表面处理条件下的金刚石成核密度。尝试了在低真空（10－1Pa量级）条件下，去除表面的氧化硅及吸附活性的含碳原子，以提高金刚石的成被密度，得到了较理想的结果，成核密度为109／cm2。     

镍衬底上定向金刚石膜的成核与生长

提出了一种包括晶粒接种、高温退火、成核、生长四过程的薄膜沉积新方法 ,用射频等离子体增强热丝化学气相沉积系统 ,在Ni衬底上制备了定向金刚石膜。通过对成核和生长两过程工艺条件的研究 ,掌握了提高成核密度和金刚石定向生长规律。实验还表明 ,膜与Ni衬底之间未见Ni C H界面层的形成     

镍衬底上定向金刚石膜的成核与生长

提出了一种包括晶粒接种、高温退火、成核、生长四过程的薄膜沉积新方法,用射频率等离子体增强热丝化学气相沉积系统,在Ｎｉ衬底上制备了定向金刚石膜。通过对成核和生长两过程工艺条件的研究,掌握了提高成核密度和金刚石定向生长规律,实验还表明,膜与Ｎｉ衬底之间未见Ｎｉ－Ｃ－Ｈ界面层的形成。     

用MPCVD法在WC—Co刀具上沉积金刚石薄膜

研究了硬质合金基体的预处理对金刚石沉积的影响,并确定了用MPCVD法在WC-Co刀具上沉积金刚石薄膜的工艺参数。采用了一些提高成核密度和沉积速率的方法,用SEM、XRD和Raman对金刚石薄膜的性质进行了分析。结果表明,合适的预处理可以有效的抑制钴的溢出并提高薄膜的质量。     

基片预处理对MWPCVD金刚石薄膜的影响

利用自行研制的石英钟罩式微波等离子体化学气相沉积金刚石薄膜装置，研究了硅基片的不同预处理方式对沉积结果的影响。通过扫描电子显微镜形貌观察和喇曼谱分析表明，基片预处理能提高形核密度；用于预处理的金刚石研磨膏的粒度不同，影响金刚石薄膜沉积时的形核密度、晶形和薄膜的质量；表面划痕对沉积金刚石薄膜的影响具有双重性。     

铁基底上扩散感应的CVD金刚石成核

在硅和铁基底上同时进行ＣＶＤ 金刚石的沉积,利用硅基底上的金刚石成核感应金刚石在铁基底上直接成核。研究表明,硅和铁基底上不同的沉积过程导致了铁基底上碳原子表面扩散的加强,从而促成了ＣＶＤ 金刚石在铁基底上的直接成核。表面扩散对ＣＶＤ 金刚石成核有重要影响。     

Coating of diamond-like carbon nanofilm on alumina by microwave plasma enhanced chemical vapor deposition process

Diamond-like carbon (DLC) nanofilms with thickness varied from under one hundred to a few hundred nanometers have been successfully deposited on alumina substrates by microwave plasma enhanced chemical vapor deposition (MW-PECVD) process. To obtain dense continuous DLC nanofilm coating over the entire sample surface, alumina substrates were pre-treated to enhance the nucleation density. Raman spectra of DLC films on samples showed distinct diamond peak at around 1332 cm(-1), and the broad band of amorphous carbon phase at around 1550 cm(-1). Full width at half maximum height (FWHM) values indicated good formation of diamond phase in all films. The result of nano-indentation test show that the hardness of alumina samples increase from 7.3 +/- 2.0 GPa in uncoated samples to 15.8 +/- 4.5-52.2 +/- 2.1 GPa in samples coated with DLC depending on the process conditions. It is observed that the hardness values are still in good range although the thickness of the films is less than a hundred nanometer.     

CVD金刚石成核的最新研究

研究了化学气相条件下金刚石在非均匀研磨硅基底表面及镜面基底和均匀研磨基底边缘及角域处的成核行为。发现ＣＶＤ金刚石成核不仅依赖于沉积区缺陷，更主要由缺陷的锐度决定，即缺陷加强ＣＶＤ金刚石成核的锐度效应。在对无序碳上ＣＶＤ金刚石成核研究的基础上，讨论了ＣＶＤ金刚石成核的机理，并由此阐明了各种表面预处理及负偏压等增强ＣＶＤ金刚石成核的微观过程。     

微波等离子体化学气相沉积法在硅片上同时生长碳化硅和金刚石

研究了衬底温度、核化密度、衬底表而预处理等工艺参数对微波等离子体化学气相沉积法在硅片上同时生长碳化硅和金刚石的影响.采用扫描电镜、X-射线衍射、喇曼光谱和红外光谱对样品进行了表征.结果表明:从高核化密度生长的金刚石膜中探测不到碳化硅;不论对硅衬底进行抛光预处理还是未抛光预处理,从低核化密度牛长的金刚石厚膜中总能探测到碳化硅.碳化硅生长在硅衬底上未被金刚石覆盖的地方,或者是在金刚石晶核之间的空洞处.碳化硅形成和金刚石生长是同时发生的两个竞争过程.此研究结果为制备金刚石和碳化砟复合材料提供了一种新的方法.     

Diamond formation on carbon/carbon composite

A carbon/carbon composite was used as substrate for low-pressure diamond deposition. To enhanced diamond nucleation on carbon/carbon composites, a total of ten surface preparation methods have been investigated. These methods involved the use of atomic hydrogen etching, mechanical polishing, sonication, or coating. Diamond nucleation was found to occur on either the defects of the carbon/carbon composite substrates or diamond particulate left on the substrates. The defects were created primarily by atomic hydrogen etching during the coating process. Seeding with diamond powders was performed by dip coating, sonication, or spray-coating processes. It was found that these seeding processes resulted in excellent nucleation of diamond.     

CVD nanocrystalline diamond coatings on Ti alloy: A synchrotron-assisted interfacial investigation

Diamond coating on Ti-6Al-4V alloy was carried out using microwave plasma enhanced CVD with a super high CH₄ concentration, and at a moderate deposition temperature close to 500 °C. The nucleation, growth, adhesion behaviors of the diamond coating and the interfacial structures were investigated using Raman, XRD, SEM/TEM, synchrotron radiation and indentation test. Nanocrystalline diamond coatings have been produced and the nucleation density, nucleation rate and adhesion strength of diamond coatings on Ti alloy substrate are significantly enhanced. An intermediate layer of TiC is formed between the diamond coating and the alloy substrate, while diamond coating debonding occurs both at the diamond-TiC interface and TiC-substrate interface. The simultaneous hydrogenation and carburization also cause complex micro-structural and microhardness changes on the alloy substrates. The low deposition temperature and extremely high methane concentration demonstrate beneficial to enhance coating adhesion strength and reduce substrate damage.     

Fluidized bed micro-machining and HFCVD of diamond films onto Co-cemented tungsten carbide (WC-Co) hardmetal slabs

The effect of fluidized bed (FB) treatment upon hot filament chemical vapor deposition (HFCVD) of polycrystalline diamond films onto WC-Co hardmetal substrates was investigated. Several scenarios to make the substrates ready for HFCVD were, comparatively, evaluated and the resulting diamond films were examined in terms of their morphology and adhesion. The diamond grain density was measured by scanning electron microscopy. The adhesion of continuous diamond film to substrate was evaluated by the reciprocal of the slope of crack radius-indentation load functions. Surface binder dissolution followed by FB treatment (PF pretreatment) allowed very high diamond nucleation density and smaller grain size. The adhesion of films grown on PF pretreated substrates was found to be very close to that of films deposited on hardmetal slabs pretreated by Murakami's reagent followed by Co etching with Caro's acid and seeded with diamond suspension in an ultrasonic vessel (MPS pretreatment). However, diamond coatings on MPS pretreated samples exhibited a rougher surface morphology as a result of both lower diamond nucleation density and larger substrate surface roughening by Murakami's etching. Based upon experimental findings, our newly developed PF pretreatment was found to be a very promising technique in substrates conditioning as well as in promoting adherent, uniform and smooth diamond coatings onto hardmetal tools and wear parts.     

CATALYST EFFECT FOR DIAMOND NUCLEATION IN THE LOW PRESSURE PROCESS

The fundamental study of diamond nucleation on several kinds of substrates using the hot-filament CVD method, was carried out. To investigate the diamond nucleation density, the substrate which coated with the catalytic materials by the vacuum deposition was utilized. Diamond particles scarcely grew on a normal Si wafer, but a catalytic material promoted the growth of diamond on the Si substrate. The catalytic material increases the diamond nucleation density as compared with any other substrates with a surface treatment. The particles grown on the substrates have been examined by means of x-ray diffraction and scanning electron microscopy, and identified as diamond.     

ON THE EFFECTS OF PHYSICAL ABRASION ON NUCLEATION AND GROWTH OF DIAMOND ON SILICON USING HOT FILAMENT CHEMICAL VAPOR DEPOSITION

Hot-filament Chemical Vapor Deposition is a simple and widely used technique for synthesis of diamond films on silicon substrates. Scratching or abrasion of the substrate surface with either diamond particles or diamond paste is a common practice, but often escapes mention in the reported literature. In such instances it is not clear whether the diamond film being grown is done so on diamond or tetrahedrally co-ordinated carbon nuclei left behind on the substrate. Attempts to address this issue must be made in order to facilitate a better understanding of the nucleation and growth processes. In this paper, various methods of physical abrasion, average size of scratch sites, as well as totally unscratched surfaces are examined both before and after growth of diamond using Raman spectroscopy and Scanning Electron Microscopy (SEM). These studies suggest that scratching of the surface with diamond particles is not strictly necessary, but does hasten nucleation. High scratch densities yield the most rapid growth. The average surface roughness rather than the material source of scratching appears to accelerate the nucleation process. This work underscores the importance of characterizing the substrate surface prior to any deposition.