微波等离子体条件下硬质合金刀片中钴的扩散规律对金刚石涂层的影响

利用化学脱钴处理后的硬质合金刀片在微波等离子体条件下沉积金刚石薄膜,用电子能谱仪(EDS)检测发现经化学酸蚀处理后的硬质合金刀片表面的钴含量基本在0.3%左右,对于金刚石膜的形核及生长几乎没有大的影响,膜层致密、晶型良好;但是在长时间的高温沉积过程中,钴逐渐向表面扩散,如900℃条件下10h后刀片表面钴含量可达2.02%,可能对金刚石薄膜与基体之间的附着产生很大的影响,导致金刚石薄膜刀具使用使命的降低。     

不同硬质合金基体对(类)金刚石薄膜沉积过程的影响

本文采用 CH_4—H_2—O_2微波等离子体化学气相沉积法在硬质合金基体上沉积金刚石薄膜,研究 YG(WC-Co)及 YT(WC—TiC—Co)两类硬质合金作基体对沉积过程及沉积速率的影响.阶段性研究结果表明,在 YT 类硬质合金上沉积金刚石薄膜的沉积速率和硬度均优于在 YG 类上的,TiC 对金刚石薄膜的沉积效果有明显的有利作用.本文还用扫描电镜观察分析了金刚石薄膜的形核长大过程.     

金刚石薄膜的形核研究

本文介绍了当前金刚石薄膜形核的现状及用热丝化学气相沉积法在不同的衬底上沉积金刚石膜，对Si、Ni、Cu三种衬底生长的金刚石膜进行研究如何增大形核密度、提高形核质量。得到了制备高密度和高质量的金刚石膜的方法。     

多排热丝沉积大面积金刚石薄膜中热丝参数的影响

根据热丝化学气相沉积法制备大面积金刚石薄膜工艺中热丝与衬底之间的几何关系,建立了该系统的热传递模型,利用计算机辅助数值解方法,给出了衬底温度与衬底表面的热辐射能量密度随热丝数量、热丝与衬底间距变化的关系．并利用该方法设计了沉积面积为100mm×100mm的金刚石薄膜的最佳热丝几何参数．     

射频磁控溅射制备类金刚石薄膜

采用射频磁控溅射法在Si和Ti合金基体上沉积出类金刚石(DLC)薄膜.利用拉曼光谱仪、划痕仪和扫描电子显微镜分析了DLC薄膜的结构、膜基附着力和表面形貌.结果表明:射频磁控溅射法能够制备出表面平整、结构致密的DLC薄膜;同时基体材料的不同不会影响DLC薄膜的键合结构,Si基体上涂层附着力为30N,Ti基体上膜基结合力大于40 N.     

磁激励RF-PECVD法低温制备类金刚石薄膜及其特性

采用磁激励射频等离子体增强化学气相沉积(M-RF-PECVD)方法,室温下分别在玻璃和Si(100)衬底上制备类金刚石(DLC)薄膜,通过扫描电镜(SEM)、傅里叶红外光谱(FTIR)和Raman光谱对不同沉积条件下制备的薄膜进行表征。结果表明,在反应压强为30 Pa、入射功率为50 W、CH4/Ar=5/90、衬底温度为40℃的实验条件下,制备的含氢DLC薄膜表面平整、结构致密,膜基结合度良好,薄膜中以sp3键为主。     

采用Cu/Ti过渡层沉积金刚石薄膜刀具的界面结构

研究了硬质合金基底上Cu/Ti作过渡层化学气相沉积(CVD)金刚石薄膜的界面特性.利用激光Raman谱分析了过渡层不同生长阶段金刚石薄膜的质量的影响.采用SEM、EDS对金刚石薄膜硬质合金刀具横截面的结构进行了研究.结果表明:基体中的Co被Cu/Ti作过渡层有效的抑制住;Cu向基体内的扩散改善了基体的性能,提高了界面层金刚石薄膜的质量;Ti的引入促进了金刚石的形核,减少了界面处晶粒间的空隙,提高了金刚石薄膜与基体表面的实际接触面积.     

表面覆盖氮化硼膜的金刚石膜的场发射特性

利用热丝化学气相沉积（HFCVD）方法在Si衬底上生长了4μm厚的金刚石膜,然后利用射频磁控溅射方法在金刚石膜上沉积了100nm厚的六角氮化硼（h—BN）薄膜．在超高真空系统中测试了覆盖氮化硼（BN）薄膜前后金刚石膜的场发射特性,结果表明覆盖BN薄膜后的金刚石膜的场发射特性明显提高,开启电场由14V／μm升到8V／μm．F—N曲线表明,覆盖BN薄膜后的金刚石膜在强电场区域的场增强因子有所降低,这可能归因于场发射点随着电场的增强而改变．     

衬底温度对热丝法生长纳米金刚石膜的影响

采用热丝化学气相沉积法在氩/丙酮/氢气体系中研究衬底温度对纳米金刚石膜生长的影响,使用扫描电子显微镜、X射线衍射仪、拉曼光谱仪对金刚石膜进行检测.结果表明衬底温度对金刚石膜的生长模式、形貌、粒径和生长速率有很大影响.在750℃衬底温度下生长模式为颗粒状生长模式,呈现纳米金刚石结构,生长速率达到8.45μm/h;随着衬底温度的降低,金刚石晶粒粒度逐渐变大,由纳米金刚石向微米金刚石转变,生长模式变为柱状生长模式,生长速率逐渐降低;在600℃衬底温度下变为微米金刚石,生长速率下降到1.95μm/h.     

不同碳源对金刚石薄膜制备的影响

采用等离子辅助热丝化学气相沉积(PAHFCVD)装置,分别用甲烷和乙醇为碳源进行了金刚石薄膜的制备。并运用X射线衍射仪(XRD)和扫描电子显微镜(SEM)测试手段对沉积的金刚石薄膜进行了观察分析。结果表明,用乙醇制备的金刚石薄膜比甲烷制得的金刚石薄膜的生长率要高,膜的缺陷少、颗粒均匀。     

Influence of methane on hot filament CVD diamond films deposited on high-speed steel substrates with WC-Co interlayer

Diamond films were deposited on high-speed steel substrates by hot filament chemical vapor deposition (HFCVD) method. To minimize the early formation of graphite and to enhance the diamond film adhesion, a WC-Co coating was used as an interlayer on the steel substrates by high velocity oxy-fuel spraying. The effects of methane content on nucleation, quality, residual stress and adhesion of diamond films were investigated. The results indicate that the increasing methane content leads to the increase in nucleation density, residual stress, the degradation of quality and adhesion of diamond films. Diamond films deposited on high-speed steel (HSS) substrate with a WC-Co interlayer exhibit high nucleation density and good adhesion under the condition of the methane content initially set to be a higher value (4%, volume fraction) for 30 min, and then reduced to 2% for subsequent growth at pressure of 3 kPa and substrate temperature of 800 °C.     

WC-Co硬质合金上高质量金刚石薄膜的制备

采用微波等离子体化学气相沉积法在硬质合金基体上制备金刚石薄膜.研究了铜过渡层和酸蚀脱钴两种基体前处理工艺以及在施加铜过渡层的情况下,不同的沉积气压和基片温度对金刚石薄膜的质量的影响.结果表明:在施加铜过渡层后,在适中的沉积条件下(沉积气压6.0 kPa,基片温度约为780℃)可得到质量较好的金刚石薄膜.     

CVD条件对金刚石薄膜／钼基体界面层的影响

用微波等离子体化学气相沉积法（MPCVD）在Mo基片上沉积金刚石薄膜时,界面层钼的碳化程度与初始沉积条件有关,利用XRD,SEM,EDS,对界面层进行的研究表明：在化学气相沉积的开始阶段,较低的甲烷浓度有利于碳向基体内的扩散从而让表面的Mo充分碳化,形成富含Mo2C的界面层,甲烷浓度过高时有利于金刚石的形核而不利于碳向基体内的扩散,在金刚石薄膜的生长过程中,碳向基体内的扩散很少,界面层的组成结构保持不变。     

基片预处理对CVD金刚石薄膜形核的影响

微波辅助等离子体化学气相沉积法是目前低压气相合成金刚石薄膜方法中应用最普遍、工艺最成熟的方法,形核是CVD金刚石沉积的第一步．利用微波辅助等离子体化学气相沉积装置,研究了硅基片预处理方式对金刚石薄膜形核密度的影响．在工作气压为5-8kPa,微波功率为2500—5000W,甲烷流量为4-8cm^3／min,氢气流量为200em3／min,沉积温度为500℃-850℃的条件下,在单晶Si基片上沉积金刚石薄膜．通过扫描电子显微镜形貌观察表明,基片预处理能够显著提高金刚石形核密度,同时用拉曼光谱表征了金刚石薄膜的质量,     

硬质合金刀片上微波等离子沉积(类)金刚石薄膜结构

本文报导采用最新的微波等离子体技术在硬质合金刀具上沉积的碳膜的结构.经扫描电镜、拉曼光谱、X射线衍射和光电子能谱分析,确定此沉积膜为类金刚石薄膜,其结构既不同于具有完整空间排列规律的金刚石结构,也不同于空间排列无层次的无定形碳膜结构,而是介于二者之间. 扫描电镜观察还表明,沉积膜与基体附着性和耐磨性能良好。     

Influence of negative bias voltage on the mechanical and tribological properties of MoS<Subscript>2</Subscript>/Zr composite films

MoS2/Zr composite films were deposited on the cemented carbide YT14 (WC+14%TiC+6%Co) by medium-frequency magnetron sputtered and coupled with multi-arc ion plated techniques.The influence of negative bias voltage on the composite film properties,including adhesion strength,micro-hardness,thickness and tribological properties were investigated.The results showed that proper negative bias voltage could significantly improve the mechanical and tribological properties of composite films.The effects of negative ...     

Deposition of crackless freestanding diamond films on Mo substrates with Zr interlayer

The Mo substrate with Zr interlayer,namely composite substrate,was employed to solve the problem of crack formation in the freestanding diamond film deposition.Freestanding diamond films deposited on the composite substrates by the direct current arc plasma jet chemical vapor deposition(CVD) method were investigated with scanning electron microscopy(SEM),X-ray photoelectron spectroscopy (XPS),X-ray diffraction(XRD),and Raman spectroscopy.In addition,the stress distribution during the large area freestand...     

Nanodiamond films deposited at moderate temperature on pure titanium substrate pretreated by ultrasonic scratching in diamond powder suspension

Nanocrystalline diamond （NCD） film deposition on pure titanium and Ti alloys is extraordinarily difficult because of the high diffusion coefficient of carbon in Ti, the large mismatch in their thermal expansion coefficients, the complex nature of the interlayer formed during diamond deposition, and the difficulty to achieve very high nucleation density. In this investigation, NCD films were successfully deposited on pure Ti substrate by using a novel substrate pretreatment of ultrasonic scratching in a diamond powder-ethanol suspension and by a two-step process at moderate temperature. It was shown that by scratching with a 30-μm diamond suspension for 1 h, followed by a 10-h diamond deposition, a continuous NCD film was obtained with an average grain size of about 200 nm. Detailed experimental results on the preparation, characterization, and successful deposition of the NCD films on Ti were discussed.     

脉冲多弧离子镀沉积类金刚石薄膜的牢固度研究

利用脉冲多弧离子镀技术在硅基片上沉积类金刚石薄膜．分析了类金刚石薄膜的牢固度与各种工艺条件的关系．实验结果表明：基片的清洗、基片温度、主回路电压、脉冲频率、烘烤处理都强烈影响类金刚石薄膜的牢固度．同时从理论上分析了利用离子束辅助蒸发工艺可以进一步提高类金刚石薄膜的牢固度