共查询到20条相似文献,搜索用时 187 毫秒
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该石墨加热体是哈尔滨电碳研究所根据三角形聚晶金刚石的需要研制成功的新产品。该产品具有工艺先进、抗压强度高、密度大、电阻适中、纯度高等特点,适于六面顶合成聚晶三角形金刚石用。 相似文献
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本文以六面顶压机合成工艺为研究对象,通过碳源及外部条件对人造金刚石单晶生长的影响,提出了优质金刚石单晶的合成工艺并论及其可行性。文章特别指出,合成优质金刚石应该有效的控制成核及生长速度,把生长控制点限制在“V”形区中小范围内研究,对生产实践有一定的指导作用。 相似文献
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在国产六面顶高压设备上,通过触媒溶剂的熔渗技术,成功制备出了优质的生长型金刚石聚晶(PCD)。为了研究合成温度对生长型金刚石聚晶的影响,分别采用光学显微镜和扫描电镜(SEM),对压力为5.6GPa、不同合成温度条件下制备的生长型金刚石聚晶的微观形貌进行了测试分析,并借助能谱面扫描对聚晶样品内部成分分布进行了检测。研究了不同合成温度条件下触媒溶剂的熔渗和金刚石微晶的再生长特征。结果表明,不同的合成温度下,金刚石再生长的驱动力和速度不同,最终导致金刚石聚晶粘接效果不同。在合适的温度条件下,制备了质地均匀、致密的优质生长型金刚石聚晶。 相似文献
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许俊杰鲁森远陈孝鹏刘杰 《超硬材料工程》2021,(2):24-27
针对目前六面顶压机人工合成工业金刚石所使用的硬质合金顶锤重新进行锤面设计。经过设计,制作成品后进行测量,新锤面顶锤相比原先的增大了6.5%。设计新的工业单晶合成块结构,运用帕斯卡原理,对顶锤底面的实际压力值进行推导计算出新的合成块在合成过程中的设备所需油压,并且进行实际实验合成工业金刚石。对使用新型顶锤的六面顶压机在合成过程中测量六面顶压机梁耳处的形变量,对六面顶压机设备的安全性进行分析;对使用新型顶锤和原有顶锤所合成出的工业金刚石进行综合性评估及对比。实验结果显示新锤面顶锤合成工业金刚石在保证六面顶压机设备安全及金刚石质量稳定的情况下,金刚石产量增加约7.5%,经济效益明显增加。 相似文献
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在六面顶压机上采用粉末工艺技术进行了Φ40腔体组装高度不变和组装块高度提高合成金刚石产品的试验。分析了试验中出现的现象,表明组装块高度提高不仅提高了金刚石产品的产量,并且有效降低了万克拉顶锤的消耗。对试验效果的分析表明,合成腔体与合成压力一定的情况下,组装高度不变比组装块高度提高合成金刚石的生产效益要差很多,并且顶锤消耗也高。因此,提高组装块的高度是降低顶锤消耗、提高单次合成产量的选择方向。 相似文献
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The growth of thick single crystal synthetic diamonds by plasma-assisted chemical vapour deposition (PACVD) that are colourless and with a low impurity content is an important challenge to achieve gem-quality material. To this aim, advanced optical imaging and spectroscopy techniques are useful tools to optimize the growth process as well as to identify CVD-made diamond gems. In this paper, two thick synthetic diamond crystals with unique structural and spectroscopic properties were grown by PACVD without intentional addition of nitrogen and without any post-treatment to enhance their colour. While the first one, sample A, was 760 μm thick and exhibited a grey to greyish brownish colour quite unusual for undoped material, the second one, sample B, was exceptionally thick (3300 μm) and colourless. It was laser-cut and polished to obtain a high gem-quality round brilliant of 0.44 carat with G colour and VVS2 clarity grade. The amount, distribution and nature of defects in these synthetic crystals is discussed using a broad range of optical characterisation techniques towards growth optimization and getting a better understanding of the material properties (and their possible integration to the gem market). 相似文献
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人造金刚石的应用从最初的工业应用领域发展到宝石级人造金刚石用于珠宝行业然后又发展到纪念品钻石服务于丧事家庭和特殊礼品等。文章阐述了工业用人造金刚石、宝石级人造金刚石与纪念品钻石的最新进展以及工业用人造金刚石在高科技与各工业部门的最新应用。全面反映国际工业用人造金刚石、宝石级人造金刚石和纪念品钻石技术的当前发展水平以及人造金刚石的未来发展趋势。此外,对国际上主要的工业用人造金刚石生产企业以及宝石级人造金刚石与纪念品钻石生产厂家的发展作简单介绍。 相似文献
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《Diamond and Related Materials》1999,8(11):2036-2042
This paper describes a technique on the pressure and temperature control in flat-belt (FB) type high pressure apparatus to conduct stable diamond synthesis study. We present results on the reproducibility of the sample pressure and temperature in different sets of diamond synthesis runs. We propose a method of monitoring these variations by the measurements of anvil displacement as a function of press load, and of heater resistance as a function of input power to the heater in every high pressure run. We examined pressure and temperature region of diamond formation in graphite-solvent metal systems, and propose a method to estimate the absolute pressure and temperature of the sample based on the graphite–diamond equilibrium curve. From these data, we conclude that the pressure and temperature of the sample in FB type high pressure apparatus can be estimated and controlled within about 3%. 相似文献
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人造金刚石的应用从最初的工业应用领域发展到宝石级人造金刚石用于珠宝行业然后又发展到纪念品钻石服务于丧事家庭和特殊礼品等。文章阐述了工业用人造金刚石、宝石级人造金刚石与纪念品钻石的最新进展以及工业用人造金刚石在高科技与各工业部门的最新应用。全面反映国际工业用人造金刚石、宝石级人造金刚石和纪念品钻石技术的当前发展水平以及人造金刚石的未来发展趋势。此外,对国际上主要的工业用人造金刚石生产企业以及宝石级人造金刚石与纪念品钻石生产厂家的发展作简单介绍。 相似文献
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拉曼光谱通过测定金刚石微粉颗粒的晶体结构及内部缺陷和杂质含量评价微粉强度品级,是一种科学、有效、能快速检测金刚石微粉强度品级的方法。根据拉曼光谱测定金刚石微粉强度品级,研究了金刚石微粉强度与金刚石单晶原料强度、金刚石原材料的合成时间、微粉生产工艺和微粉表面处理工艺之间的关系。结果表明,金刚石微粉的强度虽然与原材料强度品级密切相关,但并不呈线性比例增加;金刚石原材料的合成时间对金刚石微粉品级的影响更大;金刚石微粉破碎过程会造成微粉颗粒的内部损伤和内应力的增加,破碎分选不同料斗的相同粒度的微粉品级会有比较大的差别;强酸强碱处理会明显降低金刚石微粉的强度;用选出破碎料后的残余料做成的微粉强度品级会大幅度降低。以上结果有助于指导控制金刚石微粉生产中对强度的处理。 相似文献
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《Diamond and Related Materials》2000,9(9-10):1691-1695
The synthesis of thin diamond films using various chemical vapor deposition methods has received significant attention in recent years due to the unique characteristic of diamond, which make it an attractive candidate for a wide range of applications. In order to grow diamond epitaxially, the proper control of diamond nucleation on mirror-polished Si is essential. Adding the negative bias voltage to the substrate is the most popular method. This paper has proposed a new method to greatly enhance the nuclear density. Under very low pressure (1 torr), the high-density nucleation of diamond is achieved on mirror-polished silicon in a hot-filament chemical vapor deposition (HFCVD). Scanning electron microscopy has demonstrated that the nuclear density can be as high as 1010–1011 cm−2. Raman spectra of the sample have shown a dominant diamond characteristic peak at 1332 cm−1. The pressure effect has been discussed in detail and it has been shown that the very low pressure is a very effective means to nucleate and grow diamond films on mirror-polished silicon. Extraordinary pure hydrogen (purity=99.9999%) was used as the source. Compared with the highly pure hydrogen (purity=99.99%), we found that the density of nucleation was greatly increased. The residual oxygen in the hydrogen displayed a very obvious negative effect on the nucleation of diamond, although it can accelerate the growth of diamond. Based on these results, it was suggested that the enhanced nucleation at very low pressure should be attributed to an increased mean free path, which induced a high density of atomic hydrogen and hydrocarbon radicals near the silicon surface. Atomic hydrogen can effectively etch the oxide layer on the surface of silicon and so greatly enhance the nucleation density. 相似文献
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用国产SPD6×1200型六面顶压机,在Fe粉末触媒和石墨(Fe-C)体系中添加不同比例的H2O,高温高压条件下合成出了金刚石单晶。通过扫描电子显微镜和Mossbauer谱研究了合成样品中金刚石的成核状态和Fe-C-H2O体系中H2O对金刚石成核的影响。结果表明:在5.7GPa,1600℃条件下,当H2O的质量含量少于5%时,Fe-C-H2O体系可合成出金刚石;随着Fe-C-H2O体系中H2O含量的增加,样品中金刚石成核量逐渐减少;当H2O含量达到5%时,金刚石将不能成核生长。在合成过程中,Fe-C-H2O体系中的Fe与H2O首先发生氧化还原反应,生成FeO和FeHx。与Fe-C体系相比,H2O对金刚石成核具有明显的抑制作用,而且随着H2O含量的增加,抑制作用越明显。讨论了H2O对金刚石成核和生长抑制的机理。 相似文献