共查询到19条相似文献,搜索用时 926 毫秒
1.
2.
在热丝化学气相沉积法(HFCVD)中,以甲烷和氢气的混合物作为反应气源,通过调整和改变反应过程中反应压力、甲烷的浓度比例,在硬质合金铣刀表面沉积了常态和微米、纳米复合形态的金刚石薄膜。通过电子显微镜对金刚石复合薄膜的表面形貌和结构特征进行分析,并在石墨电极、石墨热成型模具等的实际生产加工中,根据刀具的使用时间和磨损状态对复合涂层的结合力和加工综合品质加以验证。结果表明,CVD金刚石沉积晶粒的大小随反应气体沉积气压的变化而变化,调整不同反应阶段的气体压力等参数可以得到复合形态的金刚石薄膜。复合金刚石膜具有更好的结合力和表面平整度,在实际刀具使用过程中可以得到更好的加工表面质量,并显著延长刀具寿命,具有较高的应用价值。 相似文献
3.
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 相似文献
4.
采用热丝化学气相沉积方法,以Ar+CH4+H2混合气体作为气源,通过改变氩气浓度,在单晶硅(100)基片上沉积纳米金刚石膜;采用扫描电子显微镜、原子力显微镜、X射线衍射仪和拉曼光谱仪等分析了纳米金刚石膜的形貌、微结构以及残余应力。结果表明:随着氩气浓度的增大,膜的晶粒尺寸逐渐减小到纳米级;由于晶粒细化导致膜内残余应力由拉应力变为压应力,并且压应力随氩气浓度的增大呈现先增大后减小的趋势;当氩气体积分数为98%时,即在贫氢的气氛中成功获得了平均晶粒尺寸为54 nm、均方根粗糙度约为14.7 nm的纳米金刚石膜。 相似文献
5.
6.
7.
8.
对传统HFCVD金刚石膜沉积设备进行小型化改进,分析了传统沉积设备在真空系统和衬底机构结构上的不足之处;介绍了小型化CVD金刚石膜沉积设备的系统构成;详细描述了该小型化设备的真空系统和衬底摆动机构。该系统具有均匀的表面温度场和很高的运行稳定性,可以用于纳米金刚石薄膜和金刚石厚膜的沉积,制备的纳米金刚石薄膜晶粒大小基本上都在200 nm以下,纳米硬度为(450~700)GPa;沉积的金刚石厚膜直径达93 mm,晶粒完整均匀。 相似文献
9.
利用非平衡磁控溅射与离子源复合沉积技术,以高纯甲烷和氮气作反应气体,钨为溅射靶,在40Cr、Si(100)基片和不锈钢基体上分别制备了厚度约为2μm的掺杂钨类金刚石膜,并在类金刚石膜与基体间沉积了过渡层;应用X射线衍射、拉曼光谱、俄歇电子能谱等手段分析了掺杂钨类金刚石膜的显微结构和表面成分;应用球盘摩擦磨损试验机以及纳米硬度计等测试了膜的硬度、摩擦性能及结合强度。结果表明:所制备的膜表面均匀、致密、光滑,具有典型的类金刚石结构特征;掺杂的钨弥散分布在无定型的碳中,一部分形成W2C微晶相;当膜中钨原子分数约为20%时,膜的硬度最高,摩擦因数也相对较小,膜基结合力在70 N以上。 相似文献
10.
11.
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。 相似文献
12.
Using recent papers on scanning electron microscopy (SEM) of chemical vapor deposition (CVD) diamond films, two analytical applications of the SEM are discussed: the morphologic investigations (secondary electron emission mode) and the recognition of impurities and defects [cathodoluminescence (CL) mode]. Studies of CVD diamond films by SEM demonstrate that the morphologies of these films are affected by synthesis conditions, especially by substrate temperature, methane concentration, and total pressure in the reactor. CL spectra and images are useful tools for clarifying the relationship between emission centers and different types of defects generated during the process of diamond crystal growth. The paper shows that the investigations of the morphology, crystallinity, local CL emission, as well as the surface distribution of CL spectra on CVD diamond films by SEM led to the correlative information for quality estimation of films in comparison with natural diamond. 相似文献
13.
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. 相似文献
14.
15.
金刚石薄膜断裂强度及形貌分析 总被引:2,自引:0,他引:2
金刚石薄膜以其优异的性能成为许多行业不可或缺的功能材料,但因金刚石薄膜制备质量差、不稳定,导致金刚石薄膜力学性能的研究一直处于探索阶段,没有得出系统全面的结论。本文利用金刚石力学试验机对自支撑金刚石薄膜断裂强度与薄膜沉积厚度、抛光与否之间的关系进行了研究,利用扫描电子显微镜SEM对金刚石薄膜的表面和断口形貌进行了分析。研究表明,自支撑金刚石薄膜断裂主要是解离断裂,且其断裂强度随着沉积厚度的增加而减低,自支撑金刚石薄膜是否经过抛光对其断裂强度的大小有显著影响。 相似文献
16.
17.
高性能CVD金刚石薄膜涂层刀具的制备和试验研究 总被引:10,自引:0,他引:10
采用电子增强热丝EACVD法,以WC-Co硬质合金刀具为衬底制备金刚石涂层刀具,研究了提高涂层附着力的衬底预处理新方法,探讨了抑制Co催石墨化作用的有效措施,提出了改善金刚石薄膜表面粗糙度CVD后处理新工艺。研究结果表明,采用了Ar-H2微波等离子体刻蚀脱碳预处理方法对于提高金刚石薄膜涂层的附着力有明显效果,添加适量粘结促进剂,可有效地抑制CVD沉积过程中钴向表层扩散引起的催石墨化作用。采用分步沉积新工艺是减小金刚石薄膜表面粗糙度的有效方法。所制备的高附着力和低粗糙度的金刚石薄膜涂层刀具切削性能明显改善,对实现高效高精度切削加工具有十分重要的意义。 相似文献
18.
A factorial design approach technique was adopted to understand the high stress abrasive behaviour of a diamond reinforced composite coating for various compositions at different loads and abrasive sizes. A linear regression equation was developed and used for understanding the influence of the diamond concentration, applied load, and abrasive sizes on the wear response. A negative value of the coefficient associated with diamond concentration, together with its interactions with the applied load; suggest that the wear rate decreases with increasing diamond concentration. By contrast, a positive coefficient suggests an increase in wear rate due to an increase in related factors such as the applied load and abrasive size. The coefficients associated with the interactions of the parameters are insignificant by comparison with the individual parameters, thereby demonstrating that the interaction effect of these parameters towards the wear rate is insignificant. The wear rate may be extracted in terms of the diamond concentration, the applied load and the abrasive grit size using the above linear regression equation. 相似文献
19.
高纯金属铕及其氧化物中14个稀土杂质的ICP-MS测定 总被引:5,自引:0,他引:5
本文针对单同位素元素铥与氧化铕基体的氧化物离子的质量数重叠,在ICP-MS谱法中无法测定的问题,研究了P_(507)萃淋树脂小型柱分离。在试验选择的分离条件下,分离周期(进样-淋洗-洗脱-再生)为2.5h。结合直接测定大部分稀土杂质,最终建立了高纯铕中14个稀土杂质元素的ICP-MS分析方法。方法测定下限(ΣRE)<5μg/g,加标回收率在92~111%范围内,RSD%<10%。方法灵敏、快速、简便,满足4~5N高纯金属铕及其氧化物产品分析的要求。 相似文献