硬度合金基体上CVD金刚石薄膜的形态表征

采用ＳＥＭ、Ｒａｍａｎ光谱、ＸＲＤ等测试方法，对直流等离子体射流ＣＶＤ法在硬质合金基体上合成的金刚石膜进行了形貌和结构分析。结果表明，该方法合成的金刚石膜形貌和质量受基体表面上的温度梯度、化学物质（原子氢、碳氢基团等）浓度梯度的影响较大。膜层内存在ＧＰａ数量级的残余压应力，微观应力很小。嵌镶块尺寸为纳米数量级，且随甲烷浓度增高而减小，由此而估算的位错密度统计平均值达１０＾１０ｃｍ＾－２数量级。综合     

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。     

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     

用EACVD方法合成金刚石薄膜

本文报道了用电子助进化学气相沉积（ＥＡＣＶＤ）方法合成金刚石膜的结果．用ｘ射线衍射喇曼散射和扫描电子显微镜等对合成的薄膜的性质及形貌进行了鉴定和观察，给出合成金刚石膜的工艺参数范围并简要讨论了工艺条件对膜合成的影响。主题词；电子助进化学气相沉积（ＥＡＣＶＤ）低温等离子体　金刚石膜国家自然科学基金资助课题     

薄膜技术

薄膜技术９９０８００１　提高金刚石膜与硬质合金结合强度的新方法——ＬｅｅＤ　Ｇ．Ｓｕｒｆａｃｅ＆ＣｏａｔｉｎｇｓＴｅｃｈｎｏｌｏｇｙ,１９９８,１００～１０１（１～３）∶１８７（英文）在硬质合金上沉积金刚石膜,由于二者热膨胀系数失配,使金刚石膜内应力较大,导致金刚石膜剥离或开裂。对基材进行改性,制备三维热力学上和成分上呈梯度变化的中间层,可提高金刚石膜与硬质合金的结合强度。在硬质合金上沉积ＷＣ,提高了硬质合金表面粗糙度,从而明显改善金刚石膜的结合强度。９９０８００２　ＣＶＤ沉积薄膜的前处理——Ａ…     

燃焰法沉积高质量金刚石厚膜的研究

研究了气体流量比（Ｏ２／Ｃ２Ｈ２）对燃焰法沉积金刚石厚膜的影响,并以约５０μｈ的较高速率沉积出了均匀、致密呈淡黄色透明状的高质量金刚石厚膜。     

Al2O3陶瓷上沉积金刚石薄膜的研究

以酒精为碳源，用热丝ＣＶＤ法对不同表面状态的Ａｌ２Ｏ３衬底进行了金刚石薄膜沉积的比较，用扫描电镜，喇曼光谱和Ｘ射线衍射等方法检测了沉积出的金刚石膜的质量，并讨论了它们对成核和生长的影响。     

微波等离子体化学气相沉积金刚石簿膜

建立了一台微波等离子体化学气相沉积金刚石薄膜的设备。该实验装置由以下几部分组成：微波源及传输系统、反应室、供气系统、真空系统和检测等五部分组成。沉积室是由长７０ｍｍ直径４６ｍｍ的石英管组成的。分别采用ＣＨ４／Ｈ２和ＣＯ／Ｈ２混合气体进行了沉积试验；研究了沉积参数对沉积金刚石膜的影响。在直径３０ｍｍ的单晶硅片和石英片上沉积出了均匀的金刚石膜。采用ＣＨ４／Ｃ２混合气体时，沉积速率在０．５～１．０μｍ／ｈ之间，这与原有的热灯丝方法相近。采用ＣＯ／Ｈ２混合气体时，沉积速率可达到１．７μｍ／ｈ。     

硬质合金表面钴含量对金刚石形核密度的影响

对比分析了经金刚石磨盘研磨、脱钴／未脱钴ＹＧ８硬质合金上蒸镀非晶碳膜预处理对金刚石形核密度的影响。结果表明，未脱钴者，金刚石的形核密度低，金刚石结晶质量差，颗粒稀少，未成膜。原因是金刚石沉积过程中，基体内部的钴会扩散或蒸发到表面，产生明显聚集和长大。而经脱钴处理者，成核密度可达１０＾８ｃｍ＾－２，颗粒尺寸１～２μｍ，金刚石结晶质量好，刻面廓分明，表面基本成膜。     

金刚石膜—硬质合金基体横截面组织的金相研究

采用MeF3金相显微镜对CVD金刚石膜－硬质合金基体横截面的组织进行了观察，重点研究了甲烷浓度对CVD金刚石膜－基横截面各组织层次的影响。结果表明：硬质合金基体的表面组织发生了显著的变化，形成了不同的组织层次，在化学侵蚀脱钴和等离子体刻蚀脱碳预处理的基础上所沉积的金刚石膜－基横截面组织层次为：金刚石膜／薄的石墨或游离碳层／细小WC层／残留脱碳层（η相十W相）／残留疏松层／YG8基体，甲烷浓度对各层次的形成和厚度有显著的影响。     

微波等离子体刻蚀处理对金刚石薄膜涂层刀具附着力和切削性能的影响

用HFCVD法在硬质合金（YG6）刀具衬底上沉积金刚石薄膜,用氢微波等离子体刻蚀的方法对衬底进行表面预处理,研究了该预处理技术对WC硬质合金衬底表面成分的影响,进一步探讨了所沉积金刚石薄膜的表面形貌和附着力,并通过难加工材料实际切削试验。研究了所制备的金刚石薄膜涂层刀具的切削性能。试验结果表明,Ar-H2微波等离子体刻蚀脱碳处理是提高金刚石薄膜附着力和改善涂层刀具切削性能的有效预处理方法。     

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     

Growth of diamond films on SiC, WC and cubic BN substrates

The growth morphology of diamond films grown on single crystals of SiC and on sintered WC and cubic BN (CBN) substrates by hot filament assisted chemical vapour deposition was examined using transmission electron microscopy and scanning electron microscopy. Diamond was found to have the form of particles on the substrates of SiC and WC in the initial stage of film growth. Both an amorphous layer and a directly bonded area were seen at the interface. Several orientation relationships, different from the cube/cube relation, were observed in these systems. On the other hand, in the case of diamond films on CBN substrates, the growth morphology of diamond was affected by the surface condition of the substrates. When CBN substrates were polished with a diamond paste before deposition, diamond grew in the form of particles. The growth morphology was changed by ion sputtering of the surface of the substrate from particle growth to uniform film growth. These results are discussed on the basis of lattice mismatch at the interface. This revised version was published online in November 2006 with corrections to the Cover Date.     

DEPOSITION OF DIAMOND FOR CUTTING TOOL APPLICATIONS

The poor adhesion of diamond film to substrates is one of the major problems for practical use in a cutting tool (1-4). in this study, sintered tungsten carbide (WC) body without Co metal, not cemented carbide, was used as the substrate (5), and the effects of surface decarburization of the substrate for improvement in the adhesion of diamond films were investigated. The surface decarburization and diamond coating were carried out in a microwave plasma CVD system. From the results of several adhesion tests, including the cutting tests, it is concluded that the good adhesion is obtained by surface decarburization of the substrate before diamond coating. The reasons for improvement in adhesion are considered by observing the interface structure between the film and the substrate. The damage mechanism of diamond coating on cutting an AI-18%Si alloy with increasing cutting speed is also discussed.     

Study on thermal stability of electroless deposited Ni-Co-P alloy thin film

The Ni–P and Ni-Co-P alloy thin films were deposited on silicon substrates with electroless technique. The solid state metallurgical reactions were investigated with silicon for the viewpoint of Co co-deposition effect. The alloy film kept amorphous state with increasing Co content even though the P content decreased. The films become more amorphous, and the thermal stability increased with increment of Co content in the deposit. The Co content was varied from 11.013 to 45.068 wt% while P content was decreased from 9.340 to 6.491 wt% by varying the concentration of components in electroless deposition baths. The thermal stability was examined by X-ray diffractometer (XRD), four probe, and atomic force microscopy (AFM). The results indicated the Ni-Co-P alloy films with lower P content show the higher thermal stability then the ordinary Ni–P films and prevent the silicidation at low temperature because the Ni crystallization formation suppressed by the co-deposition of Co.     

The nature of stresses in hot-filament chemical vapour deposited diamond thin films on WC substrates

The nature of film stresses in hot-filament chemical vapour deposited (HFCVD) diamond thin films on tungsten carbide substrates, is reported. Commercial WC substrates were subjected to various surface treatments. Subsequently, they were coated with a diamond film and examined for stresses using X-ray diffraction. All but one of the stress measurements indicated various levels of compressive stresses in the film and at the film–substrate interface. These stresses are compared with those obtained by other researchers. Intrinsic film stresses were also computed for diamond films and found to be tensile. WC drills, of 0.125 in. diameter, were also diamond coated and the stress levels measured along drill flanks and flutes. Significant variations were found in these stresses, and the results were analysed from a film–substrate adhesion perspective.     

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.     

Chemical vapor deposition of highly adherent diamond coatings onto co-cemented tungsten carbides irradiated by high power diode laser

The present investigation deals with the definition of a new eco-friendly alternative to pretreat Co-cemented tungsten carbide (WC-Co) substrates before diamond deposition by hot filament chemical vapor deposition (HFCVD). In particular, WC-5.8 wt %Co substrates were submitted to a thermal treatment by a continuous wave-high power diode laser to reduce surface Co concentration and promote the reconstruction of the WC grains. Laser pretreatments were performed both in N(2) and Ar atmosphere to prevent substrate oxidation. Diamond coatings were deposited onto the laser pretreated substrates by HFCVD. For comparative purpose, diamond coatings were also deposited on WC-5.8 wt %Co substrates chemically etched by the well-known two-step pretreatment employing Murakami's reagent and Caro's acid. Surface morphology, microstructure, and chemical composition of the WC-5.8 wt %Co substrates after the different pretreatments and the deposition of diamond coatings were assessed by surface profiler, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Wear performance of the diamond coatings was checked by dry sliding linear reciprocating tribological tests. The worn volume of the diamond coatings deposited on the laser pretreated substrates was always found lower than the one measured on the chemically etched substrates, with the N(2) atmosphere being particularly promising.     

WC-Co硬质合金表面不同去钴预处理方法的比较研究

用微波等离子体化学气相沉积(MWPCVD)制备金刚石薄膜涂层之前,采用盐酸、硝酸化学腐蚀和氢-氧等离子体对WC-Co硬质合金(YG6)基体表面进行去钴预处理。扫描电子显微镜形貌观察和X射线衍射谱分析都表明,与化学腐蚀方法相比,氢-氧等离子体处理具有独特的表面去钴效果,沉积金刚石薄膜的喇曼谱分析更证实其对涂层质量的改善,且对MWPCVD过程而言有其技术上的一些优越性。     

WC-Co硬质合金表面MW-PCVD制备金刚石薄膜去钴预处理的研究

研究了ＷＣ－Ｃｏ硬质合金刀具表面微波等离子体化学气相沉积（ＭＷ－ＰＣＶＤ）制备金刚石薄膜时不同的去钴预处理方式的影响。扫描电子显微镜形貌观察和喇曼谱分析表明，利用氢－氧等离子体处理方式有显著的去钴效果，相应沉积获得的金刚石薄膜质量相对较高。与酸腐蚀处理相比，微波等离子体化学气相沉积装置中实现氢－氧等离子体处理方式具有独特的优越性。