金刚石薄膜与基材之间过渡层技术的研究

通过ＴＥＭ观察发现在金刚石膜与单晶硅片，金刚石膜与ＡｌＮ陶瓷之间存在一层过渡层，过渡层的存在为金刚石的形核及生长提供了有利的条件，受此启发，为了改善金刚民基材的结合强度，采用磁控溅射，空心离子镀，真空蒸镀等方法在Ｍｏ片上沉积ＴｉＣ，ＴｉＣＮ（Ｃ／Ｎ＝１／２）ＴｉＣＮ（Ｃ／Ｎ＝１／１０）等薄膜，研究了它们对金刚石膜与基材的结合强度的影响。     

TiC/i-C复合硬质膜的过渡层界面和特性的研究(英文)

探讨在 i－ C（离子辅助沉积）硬质无定形碳膜和钢基基片之间加入碳化钛（ TiC）过渡层,以 增加膜 /基附着力和结合强度的各种优越性。 SEM（扫描电镜）和 EPMA（电子探针微分析）测试显 示 TiC中间过渡层与 i－ C层及基片的界面处的附着结合强度得以改善。划痕测试仪对该复合膜 测试则从另一方面提供了膜 /基结合强度提高的证据。对该复合膜的宏观机械力学性能的测试表 明,它在提高了膜 /基结合强度的同时,保持了类金刚石薄膜超高硬度和低摩擦系数的优良特性。     

掺钛类金刚石膜的微观结构研究

采用无灯丝离子源结合非平衡磁控溅射的方法,在模具钢及单晶硅基体上制备了梯度过渡的掺钛类金刚石（Ti-DLC）膜层,利用俄歇电子谱（AES）、透射电镜（TEM）、X射线光电子能谱（XPS）及X射线衍射（XRD）等手段对膜层的过渡层、界面及微观结构进行研究。结果表明：制备的膜层成分深度分布与所设计的基体/Ti/TiN/TiCN/TiC/Ti-DLC相吻合,在梯度过渡中不同膜层之间界面体现为渐变过程,结合非常良好;少量的Ti主要以纳米晶TiC的形式掺入到非晶DLC膜当中;所制备的膜层具有厚2.9μm、硬度高达25.77 GPa、膜/基结合力44 N-74 N。     

通过过渡层改善金刚石膜和基底间的结合性能

介绍了在金刚石膜和基底间通过施加过渡层以改善金刚石膜与基底间的结合性能的研究成果。金刚石膜可以通过过渡层沉积于多种基底上,如Ｓｉ、ＳｉＯ２ 、陶瓷（ＳｉＣ,Ａｌ２Ｏ３） 、钢及硬质合金基底等。过渡层有单层（ 如ＤＬＣ、Ｃ６０ 、Ｙ ＺｒＯ２ 、Ｃ Ｎ 膜、ＴｉＣ或ＴｉＮ） 和多层（ 如Ｍｏ／Ｎｉ、Ｍｏ／ＴｉＮ 或Ｂ／ＴｉＢ２／Ｂ 等） 之分,根据金刚石、过渡层及基底的晶格匹配性和热学匹配性,对于不同的基底应选择不同的过渡层。     

SiO_2层对金刚石膜初期生长影响的研究

用俄歇子能谱（AES）研究了热丝法生长金刚石膜中未经划痕处理的单晶硅衬底在不同沉积时间下的表面结构及Si，C，O元素浓度的深度分布。结果表明：在沉积过程中，随沉积时间增加时，基材表面C浓度增加，O浓度下降，但SiC过渡层的生长缓慢。700℃沉积4h时仍无结构完整的SiC层生成，这是表面SiO2层阻碍了SiC的形成。分析了不经划痕处理的基材形核率低的原因。用高分辨电镜（HREM）观察了生长良好的金刚石膜的膜—基界面，发现没有SiO2层存在。     

TiC／i—C复合硬质膜的过渡层界面和特性的研究

探讨在i-C(离子辅助沉积）硬质无定形碳膜和钢基基片之间加入碳化钛（TiC)过渡层,以增加膜/基附着力和结合强度的各种优越性,SEM（扫描电镜）和EPMA（电子探针微分析）测试显示TiC中间过渡层与i-C层及基片的界面处的附着结合强度得以改善,划痕测试仪对该复合膜测试则从另一方面提供了膜/基结合强度提高的证据。对该复合膜的宏观机械力学性能的测试表明,它在提高了膜/基结合强度的同时,保持了类金刚石薄膜超高硬度和低摩擦系数的优良特性。     

多弧离子镀Ti(C,N)/TiN多元多层膜研究

在LF6防锈铝的基体上采用多弧离子镀技术沉积了Ti(C，N)／TiN／Ti(C，N)/TiN／TiN(C，N)／TiN六层多元多层膜，并对其组织结构与性能进行了研究。结果表明：多元多层膜表面膜层均匀，未出现龟裂现象；膜与基体之间形成了纳米级厚度的Al3Ti新相层，说明膜与基体间的结合存在化学键合，结合强度良好，划痕临界载荷达79N。显微硬度达HV0．11911．0，与基体相比，其表面显微硬度提高了近20倍，耐磨性提高了10倍以上，但摩擦因数较高(μ＝0．66)，粘着对偶件磨损，使对偶件磨损较严重。     

金刚石膜上电子束蒸镀Ti／Ni／Au多层膜

经过相图分析提出了CVD金刚石膜上蒸镀Ti／Ni／Au的体系。采用该体系、富氧预处理工艺和电子束真空镀膜方法，金刚石膜和多层金属膜之间获得了良好结合强度。研究发现：富氧预处理对多金属膜和金刚石膜之间的结合强度影响显著。进一步利用俄歇电子能谱(AES)证实：C向Ti中扩散层有150nm之多，并出现了厚度约为90nm稳定含量层，说明有确定化学比的反应产物生成；富氧处理在金刚石膜与Ti金属层之间增加了氧的含量，为形成TiO和TiC提供了合适的条件。     

CVD金刚石表面金属化Cr/Cu/Ni/Au的研究

用化学气相沉积（CVD）金刚石表面金属化，制备了多层膜Cr／Cu／Ni／Au，膜层与CVD金刚石基体间的附着强度高。运用X射线衍射（XRD）、扫描电镜（SEM）和差热分析（DTA）对Cr／CVD金刚石界面进行了分析，发现在金属化温度低于300℃时，Cr与CVD金刚石之间无化学反应，并对附着机制进行了探讨。在对Cr／CVD金刚石进行热处理时发现，在474．6～970℃之间，DTA曲线有明显的吸热效应，即界面有化学反应产生。在经900℃左右热处理后，XRD分析界面有Cr3C2和Cr7C3生成。     

Si过渡层对梯度影响类金刚石薄膜结合力的影响研究

实验利用双放电腔微波-ECR等离子体源设备,采用复合PVD（physical vapor deposition）和PECVD（plasma enhanced chemical vapor deposition）的方法, 先后在NiTi基体上沉积Si和Si/α-C∶H过渡层,然后制备类金刚石薄膜.Raman光谱和透射电镜表明制备的梯度薄膜是典型的类金刚石薄膜,划痕的测试结果表明, Si过渡层沉积时间影响着梯度类金刚石薄膜与NiTi合金基体之间的结合强度,当沉积时间在60min左右时可获得具有最好结合强度的梯度薄膜,而超过或低于这个时间值会导致膜基结合强度降低.     

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。     

Stress and phase purity analyses of diamond films deposited through laser-assisted combustion synthesis

Diamond films were deposited on silicon and tungsten carbide substrates in open air through laser-assisted combustion synthesis. Laser-induced resonant excitation of ethylene molecules was achieved in the combustion process to promote diamond growth rate. In addition to microstructure study by scanning electron microscopy, Raman spectroscopy was used to analyze the phase purity and residual stress of the diamond films. High-purity diamond films were obtained through laser-assisted combustion synthesis. The levels of residual stress were in agreement with corresponding thermal expansion coefficients of diamond, silicon, and tungsten carbide. Diamond-film purity increases while residual stress decreases with an increasing film thickness. Diamond films deposited on silicon substrates exhibit higher purity and lower residual stress than those deposited on tungsten carbide substrates.     

Growth and characterization of diamond particles,diamond films,and CNT-diamond composite films deposited simultaneously by hot filament CVD

It is important to understand the growth of CNT-diamond composite films in order to improve the inter-link between two carbon allotropes, and, in turn, their physical properties for field emission and other applications. Isolated diamond particles, continuous diamond thin films, and thin films of carbon nanotubes (CNTs) having non-uniformly distributed diamond particles (CNT-diamond composite films) were simultaneously grown on unseeded, seeded, and catalyst pre-treated substrates, respectively, using a large-area multi-wafer-scale hot filament chemical vapor deposition. Films were deposited for four different growth durations at a given deposition condition. The changes in surface morphology and growth behavior of diamond particles with growth duration were investigated ex situ using field emission scanning electron microscopy and 2D confocal Raman depth spectral imaging, respectively. A surface morphological transition from faceted microcrystalline nature to nanocrystalline nature was observed as a function of growth duration in the case of isolated diamond particles grown on both unseeded and catalyst pre-treated substrates. However, such a morphological transition was not observed on the simultaneously grown continuous diamond thin films on seeded substrates. 2D confocal Raman depth spectral imaging of diamond particles showed that the local growth of CNTs did not affect the growth behavior of neighboring diamond particles on catalyst pre-treated substrates. These observations emphasize the importance of surface chemical reactions at the growth site in deciding sp² or sp³ carbon growth and the final grain size of the diamond films.     

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.     

SiC在异质衬底生长金刚石膜的作用分析

利用扫描电子显微镜 (SEM)、Raman光谱分析了Si衬底上金刚石膜核化和生长的过程 ,并着重分析了核化过程产生的SiC的性能。利用划痕法测量了在WC衬底上沉积SiC和未沉积SiC时生长金刚石膜的粘附力 ,同时还分析了WC衬底上有和没有SiC沉积层时表面附近金刚石膜的内应力。结果表明 ,SiC层大大地增强了含碳粒子的聚集和金刚石膜与衬底之间的粘附性 ,降低了金刚石膜与衬底之间的内应力     

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。     

钼片上CVD金刚石膜的界面研究

借助金相显微镜，ＳＥＭ、ＥＤＸＡ对钼片上ＣＶＤ金刚石膜的界面形貌和成分进行了研究，对比了加磁场与不加磁场所沉积的金刚石膜的横民面形态特征，结果表明：加磁场与否在ＣＶＤ金刚石膜和钼基体之间均存在数μｍ厚的Ｍｏ２Ｃ中间层，它呈细小柱状昌方式生长，该层以下的钼基体发生了再结晶细化；加磁场沉积的金刚石膜较致密，（显微）空隙数量较小、金刚石颗粒尺寸较小、金刚石膜背面粘附较多的Ｍｏ２Ｃ聚集物。压痕试验法评定的     

Deposition of diamond films on metal substrates

In this paper we report on the growth of polycrystalline diamond films on Mo, W, and Ni substrates using oxy-acetylene combustion flame technique. Effect of substrate temperature on the growth of diamond films has been studied in the temperature range 600–1100°C. The deposits and their surface morphology has been characterized by X-ray diffraction and scanning electron microscopy (SEM). A short duration pretreatment of Mo substrates by outer zone of the oxy-acetylene flame at lower substrate temperatures, results in the improvement of quality and adherence of the films. Growth of diamond as well as other intermediate compounds depending on the nature of substrates and interface layers is discussed. Paper presented at the poster session of MRSI AGM VI, Kharagpur, 1995     

DIAMOND FILMS FROM CH3OH SYSTEMS

Polycrystalline diamond films were obtained on silicon (111) substrates by the microwave plasma-assisted chemical-vapour-deposition (CVD) method from theCH₃OH+H₂ systems.When CH₃OH,CH₃COCH₃, H₂ were used as the source gases.the diamond epitaxial films were obtained on the synthesized single-crystal diamond (100), (110) and (111) substrates too. From the experimental results, we could discover that: CH₃OH, CH₃COCH₃ and other hydrocarbon gases could also be used as suitable source gases for the growth of diamond films.     

水冷反应室式MWPCVD制备金刚石膜装置研制

微波等离子体化学气相沉积(MWPCVD)是制备金刚石膜的一种重要方法.为了获得金刚石膜的高速率大面积沉积,研制成功了水冷反应室式MWPCVD制备金刚石膜的装置.装置在微波输入功率为3.0 kW时能长时间稳定运行,并在硅衬底上沉积出金刚石膜.