硬质合金上采用Cu和Cu/Ti过渡层沉积金刚石薄膜的形核分析

采用Cu和Cu/Ti作过渡层研究了硬质合金基底上金刚石薄膜的形核生长。Cu/Ti作过渡层明显的提高了金刚石在硬质合金基底上的形核密度。用扫描电子显微镜和激光Raman谱研究了金刚石薄膜的形核形貌和质量 ,并对形核差异的原因作了初步的探讨。     

负偏压形核法增强金刚石薄膜附着力研究

在微波等离子体化学气相沉积装置中 ,研究了负偏压形核对金刚石薄膜与WC 6 %硬质合金刀具附着力的影响。结果表明 ,负偏压形核不仅能增加金刚石的核密度 ,还能改善金刚石核在WC晶粒上分布的均匀性 ,增加膜基有效结合面积 ,从而增加金刚石薄膜附着力。因负偏压形核时含碳离子被偏压电场加速 ,对刀具表面产生溅射作用 ,采用铜替代置换钴的刀具 ,使用负偏压形核反而降低薄膜附着力 ;而采用磁控溅射镀铜的刀具 ,使用负偏压形核则能进一步提高金刚石薄膜的附着力。     

硬质合金表面化学镀Ni-P-金刚石粉沉积金刚石膜的研究

利用直流等离子射流装置在以化学镀Ni-P-金刚石粉为过渡层的硬质合金上沉积金刚石薄膜。采用SEM、EDS和X射线衍射仪(XRD)初步探讨了金刚石薄膜的表面形貌和物相组成。结果表明硬质合金刀片表面化学镀Ni-P后沉积金刚石薄膜,金刚石成核密度小、晶形差,难以得到结晶质量良好的金刚石膜。而在硬质合金刀片表面化学镀Ni-P-金刚石粉后沉积金刚石薄膜,成核密度比较高,晶形多为(100),但结合力较差。     

在WC-TiC-Co硬质合金基体上制备金刚石薄膜的试验研究

通过采用Cu/Ti复合过渡层在WC TiC Co硬质合金基体上制备金刚石薄膜的试验 ,研究了沉积工艺对金刚石薄膜的质量、表面粗糙度及附着力的影响。研究结果表明 ,采用Cu/Ti复合过渡层有利于提高金刚石薄膜的附着力 ;适当降低沉积温度虽然会导致金刚石薄膜中非金刚石碳含量增加 ,但有利于增强膜层附着力。     

金刚石薄膜与 WC-Co 硬质合金的附着性研究

以甲烷和氢气为气源，用热丝ＣＶＤ法，在ＷＣ－６％Ｃｏ的硬质合金基体上沉积金刚石薄膜。研究了基体表面经抛光、腐蚀、脱碳及镀中间层等不同的预处理对金刚石薄膜与基体的附着性的影响。试验结果表明：基体表面经抛光、腐蚀再经脱碳或镀ＴｉＮ中间层，可改善和提高附着性，金刚石薄膜的形核率和沉积速率有所降低；基体表面只经抛光、腐蚀预处理，金刚石薄膜的形核率和沉积速率较高，结晶性好，但附着性较差；采用分段沉积，可以提高金刚石薄膜的附着性。     

金刚石薄膜与WC—Co硬质合金的随着性研究

以甲烷和氢气为气源，用热丝ＣＶＤ法，在ＷＣ－６％Ｃｏ的硬质合金基体上沉积金刚石薄膜。研究了基体表面经抛光、腐蚀、脱碳及镀中间层等不同的预处理对金刚石薄膜与基体的随着性的影响。试验结果表明：基体表面经抛光、腐蚀再经脱碳或镀ＴｉＮ中间层，可改善和提高随着性，金刚石薄膜的形核率沉积速率有所降低；基体表面只经抛光、腐蚀预处理，金刚石薄膜的形核率和沉积速率较高，结晶性好，但随着性较差；采用分段沉积，可以提高     

Cr过渡层沉积粘附型CVD金刚石膜的机理研究

研究了电沉积层作为过渡层沉积CVD金刚石膜的工艺，在硬质合金的Cr电沉积层上用热丝法沉积出CVD金刚石膜。利用SEM分析了电沉积层的形貌，利用EPMA分析了H等离子处理后电沉积层的断面，利用SEM和Raman分析了金刚石膜的表面形貌、成分，利用XRD分析了过渡层和CVD金刚石膜的结合面．利用压痕法研究了金刚石薄膜与基体的结合力。结果表明，H等离子处理使得硬质合全与Cr镀层成为冶金结合，提高了电沉积层的结合强度；在Cr过渡层与金刚石膜之间形成的Cr3C2和Cr7C3等碳化物有利于金刚石的成核和膜基结合强度的提高。     

特形金刚石砂轮新结构的研究

随着复杂形状硬质合金刀具和制件的广泛应用,目前迫切待解决的问题是特形金刚石砂轮的结构。本文介绍国外特形金刚石砂轮的新结构,以供参考。 最初的金属结合剂特形金刚石砂轮是用来磨削复杂的硬质合金刀具的,它们由特形壳体和用电镀法以高精度镀在壳体上的金刚石层组成。这种金刚石砂轮的优点是结构简单,可合理利用金刚石,而缺点是砂轮的形状精度与制造工艺关系较大,且金刚石层会脱落。下面介绍几种先进的结构。     

CVD涂层α-Al2O3织构制备技术研究

采用化学气相沉积法在硬质合金基体上沉积具有不同织构择优的α-Al2O3涂层,通过扫描电子显微镜(SEM)、X射线衍射(XRD)分别对其微观组织和机械性能进行分析。研究结果表明,通过改善过渡层的氧化气氛,氧化铝的过渡层结构为针状物,成功制备不同织构的氧化铝涂层,涂层结合力良好。     

复杂曲面金刚石涂层刀具的制备与试验研究

以氢气和丙酮为原料,采用电子增强化学气相沉积(EACVD)法,利用改进了的化学气相沉积(CVD)装置在复杂曲面硬质合金(WCCo)钻头表面涂覆一层金刚石涂层.研究了适用于复杂曲面金刚石涂层刀具衬底预处理新方法和CVD涂层新工艺,并对碳化硅颗粒增强铝基复合材料进行了试验研究,研究结果表明,所制备的复杂曲面金刚石涂层刀具的耐用度和切削性能得到了显著提高.     

纳米碳管对MWPCVD过程增强金刚石形核的影响

利用石英钟罩式微波等离子体化学气相沉积（ＭＷＰＣＶＤ）实验装置,研究了硅基体表面沉积金刚石薄膜时纳米碳管对金刚石形核过程的影响。扫描电子显微镜（ＳＥＭ）形貌分析结果显示,纳米碳管处理能够促进金刚石形核。对非研磨基体而言,这是一种有效的增强金刚石形核的表面预处理方式。     

MPCVD法加偏压下金刚石膜的成核行为

用微波等离子体化学气相沉积法(M PCVD),探讨了在S i(100)衬底上加偏压电场情况下金刚石膜的成核行为。侧向力显微(LFM)表明偏压电场对金刚石成核有促进作用,并分析了偏压电场促进金刚石成核的机制。     

PCD刀具加工Al2O3颗粒耐磨层的应力分布有限面分析

采用有限元法分析了聚晶金刚石（PCD）刀具加工强化复合地板Al2O3颗粒耐磨层的应力分布状态。同时，采用接触分析方法，研究单颗Al2O3颗粒同PCD表面接触的力学状态。结果表明：PCD刀具前、后刀面应力分布呈不均匀状态，等效应力的最大值发生在靠近切削耐磨层的前刀面区域内。同时，接触应力分布随着PCD中单晶金刚石颗粒的晶粒尺寸呈显著变化。     

Temperature-dependent contact phenomena of PVD- and CVD-deposited DLC films sliding on the thin aluminium foil

This paper reports on tribological properties of magnetron-sputtered WC–C and chemical vapour-deposited diamond-like carbon films coated onto hard-metal surfaces when sliding on aluminium foil (0.2 mm nominal thickness) at different temperatures. The study addresses the evolution of the coefficient of friction at the interfaces of the coated hard metal and the aluminium foil under dry-lubrication conditions, in a ball-on-disc configuration. The wear mechanisms of the aluminium foil and the damage produced on the coated surfaces due to the sticking of aluminium were evaluated as a function of the deposited coating and the temperature at their interfaces. Aluminium-transfer to WC–C coated hard-metal surfaces during the sliding operation seemed to be a non-continuous process, which appeared after a certain number of sliding cycles. Temperatures above 70°C accelerated the transfer of aluminium to the WC–C tool surfaces. Chemical vapour-deposited diamond-like carbon films hindered the transfer of aluminium to the hard metal even at temperatures of around 125°C. At greater temperatures, an aluminium–aluminium tribosurface is formed at the interface, which increases the wear rate of the foils and rapidly degrades the quality of coatings of the hard-metal surfaces.     

热压条件下金刚石微粉的石墨化相变行为及对陶瓷断裂韧性的影响

研究了金刚石微粉在热压条件下的石墨化相变行为及对陶瓷材料断裂韧性的影响;初步认为在Al2O3/TiC陶瓷材料中适量添加金刚石微粉,能显著提高材料的断裂韧性,在该试验条件下,所添加的金刚石微粉已全部石墨化,由于热残余应力的作用,在氧化铝/石墨和碳化钛/石墨界面上有裂纹形成,但界面附近没有观察到明显的化学反应。     

Synthesizing diamond film on Cu,Fe and Si substrate by in-liquid microwave plasma CVD

The purpose of this study is to synthesize diamond onto Si, Cu, and Fe (SUS632J2) substrates and to analyze the effect of carbon diffusion on their surfaces. Diamond was synthesized using the in-liquid microwave plasma chemical vapor deposition (IL-MPCVD) as a novel method for synthesizing diamond on various base materials. The IL-MPCVD method is superior one due to its efficiency in terms of cost, space and speed as compared to a conventional gas phase microwave plasma CVD (MPCVD). Microwaves of 2.45 GHz generated plasma in a solution which was comprised of methanol: ethanol (M:E = 97:3). Evaluation of deposited diamond films was done by a Scanning Electron Microscope (SEM) and Raman spectroscopy. Results shows that the IL-MPCVD method can form diamond films on Cu, Si and Fe substrates. The minimum time of film formation of Cu, Si and Fe are 2.5, 3.5 and 5 min, respectively. The material that forms carbide layers such as Si is a better substrate to form diamond film by the IL-MPCVD than other metal substrates such as Cu and Fe. Synthesizing diamond directly on the Fe substrate results in poor quality layers. The effect of carbon diffusion influences diamond film nucleation and diamond growth. In order to alleviate the carbon diffusion and improve the quality of the diamond film on the Fe substrate, Si has been sputtered on the Fe substrate as an interlayer. It is found that the diamond film can be formed on a Fe substrate using a Si interlayer and that heat treatment and thickening the interlayer improve its quality.