硬质合金气态渗硼预处理及其对金刚石薄膜附着性能的影响

目的保持硬质合金预处理后基体的强度和表面光洁度,并且提升沉积的金刚石薄膜的膜基结合力。方法使用真空管式炉设备对硬质合金进行真空热处理气态渗硼,然后使用热丝化学气相沉积系统(HFCVD)沉积金刚石薄膜。之后采用X射线衍射仪、扫描电子显微镜(SEM)、能谱分析仪(EDS)、拉曼光谱仪、表面轮廓仪和洛氏压痕测试仪等对样品的结构、形貌和膜基结合性能进行了分析。结果使用真空热处理气态渗硼法可以在较短时间内完成硬质合金的硼化处理,得到以Co WB相为主的渗硼层,并且具有高温稳定性,表面硬度较未硼化处理的样品提高了15%～20%,最高硬度达到2445HV。相较于酸碱刻蚀二步法预处理,渗硼处理更加有效地改善了膜基结合力,当渗硼温度在1000℃时,可以更加有效抑制基体中的Co颗粒向外扩散,制备的金刚石薄膜质量最优,薄膜和基体的结合性能也更加优异。结论采用真空管式炉进行的热处理气态渗硼预处理法可以简单高效地实现对硬质合金的硼化处理,重复性好,并且可大批量处理,处理后沉积的金刚石薄膜有良好的膜基结合力。     

CVD金刚石薄膜及膜-基界面形态

采用直流等离子体财流CVD法在硬质合金基体上沉积了多晶金刚石薄膜,借助XRD、Raman光谱、SEM和EPMA等对金刚石薄膜及膜-基界面的结构、形貌和成分进行了研究.结果表明,结晶度高的刻面型金刚石薄膜质量、纯度较好,膜-基界面处较致密,机械锚固作用明显,结合性能较好沉积前后基体表面形貌变化很大,存在数十微米厚的脱钴-等离子体刻蚀层,等离子体刻蚀导致脱钻表面更加凹凸不平,为金刚石形核提供了有利条件.     

热丝辐射距离和W-C梯度过渡层对高速钢基体气相生长的影响

使用反应磁控溅射技术在W18Cr4V高速钢基体表面制备W-C梯度过渡层(WCGC),采用热丝化学沉积法(HFCVD),以甲烷和氢气为反应气体,在基体表面生长金刚石膜。采用场发射扫描电子显微镜(FE-SEM)、X射线衍射仪(XRD)和激光拉曼光谱(Raman)对W-C过渡层和金刚石膜进行检测分析,研究热丝辐射距离和沉积气压对WCGC与金刚石膜的的影响。结果表明:热丝辐射距离对金刚石薄膜和WCGC均有较大影响;WCGC过渡层能够在一定热丝辐射范围内降低Fe在金刚石膜沉积过程的负面影响,有效提高金刚石的形核率,在基体表面得到连续致密的金刚石膜。     

脉冲偏压磁过滤电弧离子镀TiN薄膜的组织结构及耐磨性研究

利用脉冲偏压磁过滤电弧离子镀在高速钢(M2)基底上沉积了厚约2.5μm的TiN薄膜;分别采用FESEM、GDOES、XRD和划痕试验法观察薄膜表面和断面形貌、测试薄膜成分及相结构,分析膜基结合强度,通过显微硬度计和球盘摩擦磨损试验机对比考察TiN薄膜和M2高速钢基体的硬度和耐磨性。结果表明,TiN薄膜表面光滑致密,呈现致密柱状晶结构和明显的(111)择优取向,膜基结合强度大于60 N,薄膜硬度约为26 GPa;脉冲偏压磁过滤电弧离子镀制备的TiN薄膜表现出很好的减摩和耐磨性能。     

CVD金属石薄膜及膜——基界面形态

采用直流等离子体射流ＣＶＤ法在硬质合金基体上沉积了多晶金刚石薄膜,借助ＸＲＤ,Ｒａｍａｎ,光谱、ＳＥＭ和ＥＰＭＡ等对金刚石薄膜及膜－基界面的结构、形貌和成分进行了研究,结果表明,结晶度高的刻面型金刚石薄膜质量、纯主较好,膜－基界面处较致密,机械锚固作用明显,结合性能较好,沉积前后基体表面形貌变化很大,存在数十数米厚的脱钴－等离子体刻蚀层,等离子体刻蚀导致脱钴表面更加凹凸不平,为金刚石形核提供了有利     

深冷处理对GLC多层薄膜界面结构及结合强度的影响

为了研究深冷处理后GLC多层薄膜界面结构及结合强度的变化,采用非平衡直流磁控溅射技术,在W9高速钢上沉积了含GLC功能层、Cr/C梯度层及Cr底层的类石墨碳多层薄膜,厚度约为4μm。采用液氮(-197℃)对GLC/高速钢复合体系进行深冷处理,借助XPS、SEM及TEM表征了GLC薄膜的表面、断面结构及界面微观组织;采用洛氏硬度仪定性考察了薄膜的膜基结合强度。结果表明:复合体系经深冷处理后除基体的硬度及承载能力得以提高外,多层膜各层及基体中裂纹的萌生及传播受到抑制,界面结合强度明显增强。其作用机理在于深冷处理后,Cr底层的柱状晶结构被"打破",纤维状结构消除,组织更加致密均匀;同时,Cr/C梯度层中Cr晶粒碎化平均尺寸由20 nm减小为5 nm,达到细晶强化效果。因此,膜基及层间界面结构得以改善,界面失配减小,基体及多层膜各层间的变形协调性能增强。     

铜基体预沉积铜-金刚石复合过渡层金刚石膜的制备与表征（英文）

在铜基体表面电沉积铜-金刚石复合过渡层,采用电镀铜加固突出基体表面的金刚石颗粒,最后利用热丝化学气相沉积(HFCVD)法在复合过渡层上沉积大面积的与基体结合牢固的连续金刚石膜。采用扫描电子显微镜、拉曼光谱和压痕试验对所沉积的金刚石膜的表面形貌、内应力及膜/基结合性能进行研究。结果表明:金刚石膜由粗大的立方八面体颗粒与细小的(111)显露面颗粒组成,细颗粒填充在粗颗粒之间,形成连续的金刚石膜。复合过渡层中的露头金刚石经CVD同质外延生长成粗金刚石颗粒,而铜表面与粗金刚石之间的二面角上的二次形核繁衍长大成细金刚石颗粒。金刚石膜/基结合力的增强主要来源于金刚石膜与基体之间形成镶嵌咬合和较低的膜内应力。     

负偏压在电弧离子镀沉积TiN／TiCN多层薄膜中的作用

用电弧离子镀方法在高速钢、不锈钢与铜基体上沉积合成Ti/TiCN多层薄膜,在其他参数不变的情况下只改变负偏压,着重考察不同负偏压下薄膜的沉积深度、膜基结合强度、显微硬度以及表面形貌等,研究基体负偏压在沉积多层薄膜中所起的作用。结果表明,负偏压影响沉积温度,负偏压值越大,温度越高;负偏压值增大,表面形貌中的大颗粒数量减少,薄膜质量得到改善;负偏压在－300V左右时,膜基结合强度与硬度出现对应最佳性能点的峰值。     

高速钢表面离子镀TiC薄膜及其耐磨性研究

采用多弧离子镀技术在W18Cr4V高速钢表面沉积TiC薄膜,通过场发射电镜、能谱及X射线衍射研究了薄膜表面及界面的结构与组成,并利用微量磨损仪对TiC薄膜的耐磨性进行了对比.结果表明,多弧离子镀在高速钢表面获得的TiC薄膜硬度达2900 HV0.05,薄膜表面平整致密,在TiC薄膜与基体之间存在一扩散并不明显的伪扩散层.由于TiC膜的硬度高于TiN膜且具有更低的摩擦系数,TiC膜的耐磨性优于TiN膜.     

表面纳米化对304不锈钢/CrN薄膜力学性能的影响

表面纳米化可以显著改善金属材料的表面力学性能,并促进氮、铬等原子的热扩散,文中尝试采用表面纳米化技术改善金属基体/硬质薄膜的力学性能.对304不锈钢采用表面机械研磨处理获得纳米晶粒表层,采用多弧离子镀镀方法在表面纳米化和粗晶粒的304不锈钢基体上沉积CrN薄膜.对两种膜基体系采用X射线衍射、显微硬度测试、压入法和划痕法膜基结合性能评价.结果表明,表面纳米化影响了CrN膜层的组织结构,明显提高了膜基体系的硬度和承载能力,还改善了膜层的韧性,膜基结合性能也得到提高.     

不同过渡层对钢基金刚石薄膜的影响

采用超高真空热丝化学气相沉积(HFCVD)系统,以甲烷和氢气为反应气体,在高速钢W18Cr4V基体上利用3种不同的过渡层(WC、Cr、WC/Cr)制备金刚石薄膜。采用场发射扫描电子显微镜(FE–SEM)、X射线衍射仪(XRD)、显微激光拉曼光谱仪(Raman)以及洛氏硬度计对过渡层和金刚石薄膜进行检测分析,研究了不同过渡层对金刚石薄膜形貌质量和附着性能的影响。结果表明,3种过渡层均可以有效减少钢基中Fe对金刚石薄膜的负面影响,提高金刚石的形核率;其中,采用WC/Cr过渡层时膜基间残余应力最小,仅为0.25 Gpa,附着性能最好。     

Effects of thickness and cycle parameters on fretting wear behavior of CVD diamond coatings on steel substrates

Diamond films have been grown on carbon steel substrates by hot filament chemical vapour deposition (CVD) methods. A Co-containing tungsten-carbide coating prepared by high velocity oxy-fuel spraying was used as an intermediate layer on the steel substrates to minimize the early formation of graphite (and thus growth of low quality diamond films) and to enhance the diamond film adhesion. The effects of thickness and cycle parameters on adhesion, tribological behaviour and electrochemical treatment of the diamond film were investigated. The diamond films exhibit excellent adhesion under Rockwell indentation testing (1500 N load) and in high-speed, high-load, long-time reciprocating dry sliding ball-on-flat wear tests against a Si₃N₄ counterface in ambient air (500 rpm, 200 N, 300000 cycles). Time modulated CVD (wherein the CH₄ fraction in the process gas mixture is cycled in time) is shown to yield diamond films offering an exceptional combination of low friction, high hardness, high wear resistance, as well as promising corrosion resistance.     

Effects of Ti- and Zr-based interlayer coatings on hot-filament chemical vapor deposition of diamond on high-speed steel

The prospect of obtaining good adhesion of diamond films onto steel substrates is highly exciting because the achievement of this objective will open up numerous new applications in industry. However, a major problem with depositing diamond onto steel is high diffusion of carbon into steel at chemical vapor deposition (CVD) temperatures leading to a very low nucleation density and cementite (Fe₃C) formation. Therefore, the study of the nucleation and growth processes is timely and will yield data that can be utilized to get a better understanding of how adhesion can be improved. This work focuses on the adhesion of thin diamond films onto high speed steel previously coated with various interlayers such as ZrN, ZrC, TiC, and TiC/Ti(C,N)/TiN. The role of seeding on nucleation density and the effect of diamond film thickness on stress development and adhesion has been investigated using scanning electron microscopy (SEM), x-ray diffraction (XRD), and Raman spectroscopy (RS). The main emphasis in this study lies with TiC, which for the first time proved to be a suitable layer for diamond CVD on high-speed steel (HSS). In fact, different from other interlayer materials investigated, no delamination was observed after 3 h of CVD at 650 °C when TiC was used. Nevertheless, the increase of diamond film thickness on TiC-coated HSS substrates led to delamination of small areas. This occurrence suggests that there was a distribution of adhesive toughness values at the diamond/TiC interface with the stress development being dependent on film thickness. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.     

Plasma enhanced diamond deposition on steel and Si substrates

Diamond growth on Fe-Cr-Al-Si steel and Si substrates was comparatively investigated in microwave plasma enhanced chemical vapor deposition (MPCVD) reactor with different deposition parameters. Adherent nanocrystalline diamond films were directly deposited on this steel substrate under a typical deposition condition, whereas microcrystalline diamond films were produced on Si wafer. With increasing CH4 concentration, reaction pressure, or the total gas flow rate, the quality of nanocrystalline diamond films ...     

Hexagonal diamond formation on steel substrates by negative bias microwave plasma enhanced chemical vapor deposition

This paper reports for the first time the synthesis of hexagonal diamond thin films on high-speed steel substrates by multi-mode microwave plasma enhanced chemical vapor deposition. Before deposition of the films, the substrate surface was treated by scratching with diamond powder. The deposited films were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy. The XRD patterns of (100) and (101) planes and the Raman peaks at ~ 1317-1322 cm^− 1 were observed, confirming the formation of hexagonal diamond phase in the prepared films. The effects of voltage bias on the phase formation, microstructure and hardness of the films were also studied by setting the voltage to 0, − 70, − 150 and − 190 V. The highest hardness of 23.8 GPa was found in the film having clusters of size about 550 nm deposited under a bias voltage of − 150 V. These clusters were built up of grains of size about 14 nm.     

微波等离子体刻恂对WC—Co硬质合金基体金刚石薄膜附着力的影响

金刚石薄膜的附着力是影响CVD金刚石涂层刀具切削性能的关键因素,本文采用EACVD法在硬质合金（YG6）基体上沉积金刚石涂层;用Ar-H2微波等离子WC－C0衬底进行刻蚀处理,以改变基体表面与金刚石涂层间的界面结构,提高金刚石涂层的附着力;采用压痕法评估涂层附着力,借助SEM等观察刻蚀预处理方法对膜基界面的影响,并对此进行分析和讨论。     

Hot-filament chemical vapor deposition of polycrystalline diamond coatings to interlayered steel

Zr-based nitride and carbide coatings have been deposited on high-speed steel by the cathodic arc method. Hot-filament chemical vapor deposition (CVD) has been used to deposit diamond films onto a treated steel surface. The films deposited by CVD were characterized using scanning electron microscopy, x-ray diffraction, and Raman spectroscopy to determine the surface morphology, roughness, crystal structure, and bonding characteristics. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.     

Microstructure,Mechanical, and Tribological Properties of CNx Thin Films Prepared by Reactive Magnetron Sputtering

The microstructure,mechanical,and tribological properties of the carbon nitride(CN_x) thin films with different nitrogen contents deposited on high-speed steel substrates by reactive magnetron sputtering were studied.CN_x films with nitrogen contents from 10.7 to 28.2 at.%had an amorphous structure composing of the carbon bonds of sp~2C-C,sp~2C-N,and sp~3C-N.The TiN inter-layer cause the adhesion of CN_x films enhancement.The more nitrogen concentration led to larger film hardness and friction coefficient against GCr15 steel balls,but the wear rates decreased.     

预处理对金刚石薄膜质量及结合力的影响

目的改善硬质合金表面金刚石薄膜的结合力。方法采用热丝CVD法在硬质合金基体上制备金刚石薄膜,研究对比喷砂+一步法、喷砂+两步法、Al Cr N过渡层和传统两步法这四种预处理对金刚石薄膜质量及其结合性能的影响。对预处理后硬质合金基体表面的形貌和粗糙度进行分析,并通过扫描电子显微镜、X射线衍射、拉曼光谱及洛氏硬度计表征金刚石薄膜的形貌、结构及性能。结果喷砂有利于在基体表面获得均匀分布的凹坑,提高金刚石的形核密度及均匀性,尤其改善了金刚石颗粒的团聚现象。Al Cr N过渡层虽然表面粗糙度不高,但有大量的凸起颗粒,提供了极佳的形核点,也在一定程度上优于传统两步法的表面金刚石形核密度。在金刚石薄膜沉积参数不变的前提下,传统两步法预处理获得的涂层结合力为HF4级,喷砂结合一步法和两步法获得的结合力分别达到了HF3级和HF1级,但Al Cr N过渡层的结合力表现较差。结论 Al Cr N过渡层能阻挡Co的扩散,提高了金刚石的纯度,但金刚石膜的内应力较大,结合力差。喷砂和刻蚀复合预处理不仅能提高金刚石的结晶质量和纯度,金刚石薄膜的结合力也得到改善。