金刚石厚膜的晶界对耐磨性的影响

用直流辉光等离子体化学气相沉积制备金刚石厚膜,用氢的微波等离子体对其抛光截面进行刻蚀,研究了晶界对金刚石厚膜耐磨性的影响.结果表明：在金刚石膜的生长过程中,随着甲烷流量的增加,金刚石膜的晶界从纵向排列为主过渡到网状结构,晶粒内部缺陷逐渐增加,杂质、空洞主要分布于晶界处．金刚石膜的磨耗比随着晶界密度、宽度、杂质含量及晶粒内部缺陷的增加而下降．晶界是杂质、空洞主要富集区,是影响金刚石厚膜耐磨性的主要因素．     

熔融铈快速抛光CVD金刚石厚膜及表面分析

利用熔融稀土铈(Ce)对CVD金刚石厚膜进行了抛光研究.详细讨论了工艺参数对抛光速率和表面粗糙度Ra的影响,获得了最佳抛光工艺.通过对抛光后金刚石膜表面的拉曼光谱(Raman)、俄歇能谱(AES)、扫描电镜(SEM)以及能谱(EDS)的分析,探讨了抛光机理.结果表明:该方法有很高的抛光速率,可达每小时数百微米.抛光后金刚石膜的Ra从10.845μm降低至0.6553μm.抛光的热处理工艺不但没有破坏金刚石表面的原始结构,而且由于铈对石墨的优先刻蚀,抛光后金刚石膜表面的石墨含量还大大减少.     

稀土金属抛光金刚石膜技术

研究开发了一种有效地抛光化学气相沉积金刚石厚膜的技术。该技术利用化学活性很强的稀土金属镧的金刚石的化学反应，在一定的工艺条件下可对金刚石膜进行有效的抛光。抛光绵高低与抛光温度有关，在温度大于９００℃时抛光效率较高，可达３４μ／ｈ，表面度可从原来的Ｒａ １２μｍ降至Ｒａ１．６μｍ，如用于后续的精抛光，可大大光的时间和提高抛光效率，使表面十分粗糙的金刚石厚膜的精抛光能得以经济地进行。     

ECR等离子体刻蚀增强机械抛光CVD金刚石

采用电子回旋共振(ECR)等离子体刻蚀与机械抛光相结合的方法抛光化学气相沉积(CVD)金刚石,运用扫描电镜、Raman光谱观察、分析了刻蚀与抛光后金刚石的表面形貌和质量变化,并与单纯的机械抛光相比较,研究了等离子体刻蚀对后续机械抛光的影响,结果发现:金刚石经ECR等离子体刻蚀后非晶碳含量有一定程度降低,刻蚀过程在金刚石晶面形成的疏松表面有利于机械抛光,金刚石表面平均粗糙度更加快速降低。对比实验表明等离子体刻蚀对机械抛光前期的抛光效率的增强效果更为明显,在ECR等离子体刻蚀后的金刚石样品经10min机械抛光后粗糙度从7.284下降到1.054μm,而直接机械抛光30min时金刚石的表面粗糙度为1.133μm,在机械抛光的初始阶段,等离子体刻蚀后的机械抛光效率是单纯机械抛光效率的3倍。最终,经过三次重复刻蚀后机械抛光,金刚石表面粗糙度降为0.045μm。     

CVD金刚石膜高效超精密抛光技术

CVD金刚石膜作为光学透射窗口和新一代计算机芯片的材料,其表面必须得到高质量抛光,但是现存方法难以满足既高效又超精密的加工要求.本文提出机械抛光与化学机械抛光相结合的方法.首先,采用固结金刚石磨料抛光盘和游离金刚石磨料两种机械抛光方法对CVD金刚石膜进行粗加工,然后采用化学机械抛光的方法对CVD金刚石膜进行精加工.结果表明,采用游离磨料抛光时材料去除率远比固结磨料高,表面粗糙度最低达到42.2 nm.化学机械抛光方法在CVD金刚石膜的超精密抛光中表现出较大的优势,CVD金刚石膜的表面粗糙度为4.551 nm.     

抛光对化学气相沉积金刚石自支撑膜断裂强度的影响

研究了抛光对化学气相沉积金刚石自支撑膜断裂强度的影响。结果表明,金刚石自支撑膜粗糙表面所带来的V形缺口会降低其断裂强度,而且随着膜厚的增加,降低的程度越明显,通过抛光粗糙表面,消除了V形缺口对断裂强度的影响,有利于提高金刚石膜的抗破坏能力。提出了一种金刚石膜断裂强度的经验计算方法,获得的断裂强度值更接近于金刚石膜的本征断裂强度。     

复合抛光对 CVD金刚石薄膜表面光洁度的改进研究

采用激光抛光和热化学抛光相结合的方法，对通过热丝CVD方法生长的金刚石薄膜进行了复合抛光处理．并利用X射线衍射仪（XRD）、拉曼光谱仪（Raman）、扫描电子显微镜（SEM）和原子力显微镜（AFM）对金刚石薄膜进行了表征．结果表明，所合成的金刚石薄膜是高质量的多晶（111）取向膜；经复合抛光后，金刚石薄膜的结构没有因抛光而发生改变，金刚石薄膜的表面粗糙度明显降低，光洁度大幅度提高，表面粗糙度Ra在100nm左右，基本可以达到应用的要求．     

乙醇对金刚石膜生长特性的影响

采用EA-CVD(Electron Assisted Chemical Vapor Deposition)方法制备金刚石厚膜,在反应气体(CH4+H2)中添加乙醇,在保持其它条件不变的情况下研究了不同乙醇流量对金刚石膜生长的影响.利用拉曼光谱和SEM等测试方法对金刚石膜进行了表征,证实乙醇电离时产生的氢氧键对金刚石有很强的刻蚀作用.在沉积过程中向系统中加入乙醇对金刚石膜表面形貌有显著的影响,适量的乙醇有利于提高膜品质和生长速率,但过量的乙醇会导致对金刚石表面的刻蚀加剧,使金刚石膜的生长受到抑制.     

硫化锌窗口上CVD法制备金刚石膜的研究进展

金刚石具有优异的红外透过性能,可作为硫化锌红外窗口的保护膜。但由于CVD金刚石的沉积过程会刻蚀硫化锌衬底,导致在窗口表面直接生长金刚石膜比较困难。本文主要综述了近年来通过添加过渡层沉积金刚石薄膜的方法和光学焊接金刚石厚膜的方法来增强硫化锌窗口的性能,并介绍了CVD金刚石膜的光学应用及其目前所存在的问题,最后对未来CVD金刚石膜发展的方向作出了展望。     

氢氧等离子体预处理对单晶金刚石刻蚀坑的研究

采用自制的微波等离子体化学气相沉积装置,在高温高压法合成的金刚石的衬底上外延生长单晶金刚石。实验分为两步,首先用氢氧等离子体在生长之前进行预处理刻蚀,然后外延生长30 h。利用金相显微镜和激光拉曼光谱来表征单晶金刚石刻蚀坑以及外延生长的单晶金刚石质量。研究结果表明,氧会优先刻蚀籽晶表面的缺陷和位错,可以通过刻蚀坑密度来判断衬底质量,且经过预处理刻蚀能消除单晶金刚石表面的缺陷。籽晶表面经刻蚀后会出现平底型和尖锥型两种倒金字塔型刻蚀坑,且晶体表面的原本缺陷或由抛光造成起的缺陷会随刻蚀时间延长、刻蚀强度增大而消失。经过氢氧等离子体预处理外延生长的单晶中非金刚石相杂质含量较少,结晶性高。     

CVD金刚石厚膜的稀土化合物浆料刻蚀

与现有的金刚石膜势光工艺相匹配的高效刻蚀技术,是目前研究的热点,自行研制的稀土化合物浆料对CVD金刚石厚膜进行了刻蚀研究,刻蚀过程在低于金刚石氧化点的温度下和大气环境中完成,其刻蚀结果,用扫描电子显微镜给出。实验表明,该工艺采用廉价的稀土化合物为原料,具有简单、完全、高效的特点。     

CVD金刚石厚膜刀具材料研究进展

本文对CVD金刚石厚膜刀具材料的制备技术及后加工工艺 ,VCD金刚石厚膜刀具材料的研究现状和发展前景进行了简要的综述     

LASER PROCESSING OF DIAMOND AND DIAMOND-LIKE FILMS

Laser processing of polycrystalline diamond and amorphous carbon films is shown to be a promising technology for micropatterning of these materials in electronics and other applications. By using excimer lasers, holes and pits have been formed in 10-60 μm thick diamond films by physical etching with ablation rates of up to 300 nm/pulse. The channels of micrometer scale width were created in diamond-like carbon films on silicon by chemical etching in oxygen by the scanning with a cw Ar⁺ laser beam. At laser powers below the etching threshold, a transformation of amorphous carbon to graphitic carbon allows the formation of conductive lines of different geometry in dielectric carbon layers.     

High velocity SAW using aluminum nitride film on unpolished nucleation side of free-standing CVD diamond

High performances surface acoustic wave (SAW) filters based on aluminium nitride (AlN)/diamond layered structure have been fabricated. The C-axis oriented aluminum nitride films with various thicknesses were sputtered on unpolished nucleation side of free-standing polycrystalline chemical vapor deposition (CVD) diamond obtained by silicon substrate etching. Experimental results show that high order modes as well as Rayleigh waves are excited. Experimental results are in good agreement with the theoretical dispersion curves determined by software simulation with Green's function formalism. We demonstrate that high phase velocity first mode wave (so-called Sezawa wave) with high electromechanical coupling coefficient are obtained on AlN/diamond structure. This structure also has a low temperature coefficient of frequency (TCF), and preliminary results suggest that a zero TCF could be expected.     

Hydrogenated Nanoporous Diamond Films

Nanoporous diamond films up to 20 µm thick with a pore size of 1–1.5 nm and porosities from 0.4 to 0.6 are produced by selective etching in air. The effect of hydrogen plasma processing on the IR absorption and electron paramagnetic resonance spectra of the films is investigated. The results indicate that the concentration of bonded hydrogen in the hydrogenated nanoporous diamond films attains 20 at %. The kinetics of hydrogen desorption are studied as a function of temperature.__________Translated from Neorganicheskie Materialy, Vol. 41, No. 8, 2005, pp. 928–934.Original Russian Text Copyright © 2005 by Khomich, Varnin, Teremetskaya, Poklonskii, Lapchuk, Korobko.     

大面积高光学质量金钢石自支撑膜的制备

介绍了一种新型的磁控/流体动力学控制的大口径长通道直流电弧等离子体炬，并据此设计建造了100千瓦级高功率DC Arc Plasma Jet CVD金刚石膜沉积系统，讨论了该系统采用的半封闭式气体循环系统的工作原理，以及在气体循环条件下制备大面积高光学质量金刚石自支撑膜的研究结果。     

大尺寸CVD金刚石厚膜的制备及应用

采用电子辅助化学气相沉积法（ＥＡＣＶＤ）制备了直径１２０ｍｍ、厚度１ｍｍ以上的大尺寸金刚石厚膜,这是国内已见报道的最大成膜尺寸．ＳＥＭ和Ｒａｍａｎ光谱分析表明它是一种纯晶质的多晶金刚石材料;其硬度接近天然金刚石,远高于聚晶金刚石．将这种材料加工成拉丝模具,现场拉丝结果表明其拉丝效果与天然金刚石和进口优质聚晶相当,优于国产聚晶．用这种金刚石制成的拉丝模具可广泛用于拉制钨、钼、铜和不锈钢丝．     

等离子体刻蚀处理对金刚石膜粘附性能的影响

采用直流等离子体射流ＣＶＤ法在ＹＧ８质合金基体上成功地合成了多晶金刚薄膜。通常基体表面经金刚石磨盘研磨、稀硝酸化学侵蚀脱钴预处理后，沉积的金刚石薄膜的的粘附性能仍不理想。本文首次采用原位的Ａｒ－Ｈ２等离子体射流对基体表面进行适当的轰击、刻蚀处理，显著粗化了基体表面，并使基体表面显微组织和化学成分发生重大变化，并且在合适的沉积工艺条件下，沉积的金刚石膜的粘附性能显著提高。借助ＸＲＤ、ＳＥＥＭ、ＴＥＭ     

Optimization of chemical vapor deposition diamond films growth on steel: correlation between mechanical properties, structure, and composition

In the present work we perform optimization of mechanical and crystalline properties of CVD microcrystalline diamond films grown on steel substrates. A chromium-nitride (Cr-N) interlayer had been previously proposed to serve as a buffer for carbon and iron inter-diffusion and as a matching layer for the widely differing expansion coefficients of diamond and steel. However, adhesion and wear as well as crystalline perfection of diamond films are strongly affected by conditions of both Cr-N interlayer preparation and CVD diamond deposition. In this work we assess the effects of two parameters. The first one is the temperature of the Cr-N interlayer preparation: temperatures in the range of 500 degrees C-800 degrees C were used. The second one is diamond film thickness in the 0.5 microm-2 microm range monitored through variation of the deposition time from approximately 30 min to 2 hours. The mechanical properties of so deposited diamond films were investigated. For this purpose, scratch tests were performed at different indentation loads. The friction coefficient and wear loss were assessed. The mechanical and tribological properties were related to structure, composition, and crystalline perfection of diamond films which were extensively analyzed using different microscopic and spectroscopic techniques. It was found that relatively thick diamond film deposited on the Cr-N interlayer prepared at the temperature similar to that of the CVD process has the best mechanical and adhesion strength. This film was stable without visible cracks around the wear track during all scratch tests with different indentation loads. In other cases, cracking and delamination of the films took place at low to moderate indentation loads.