文摘

用含硼T610石墨炭源材料合成透明含硼金刚石[刊,中]/王松顺//炭素,2004(3):23～25控制石墨炭源材料的硼含量是透明含硼金刚石合成的关键问题。文中叙述了透明含硼金刚石合成的效果,讨论了石墨源材料中的硼含量和合成工艺对透明含硼金刚石合成的影响,指出了提高透明含硼金刚石合成质量的方法和途径。表1参2大型整体毡炭/炭复合材料的密度分布及影响[刊,中]/方东红,李瑞珍,郝志彪//炭素,2004(3):28～32研究了采用化学气相沉积(CVD)和树脂浸渍/固化/碳化相结合的致密工艺制备的大型整体毡炭/炭复合材料的密度、开孔率及压缩强度的分布状况,分…     

用含硼T641石墨炭源合成耐热性金刚石

介绍了含硼T641石墨炭源合成耐热性高、抗氧化性好与化学惰性强的金刚石及其性质。讨论了含硼金刚石高耐热性的形成及其氧化机理。指出了进一步提高质量、耐热性、抗氧化性与化学惰性金刚石的合成途径及方法。     

含硼石墨碳源合成金刚石的试验

叙述了含硼石墨碳源合成金刚石的效果。讨论了石墨碳源含硼种类及其掺量对合成金刚石效果及其晶体生长性能的影响。在对含硼石墨碳源多种性能进行测试与分析的基础上，指出了选择合成金刚石碳源材料的原则和必要性。     

特殊类含硼金刚石合成的实验研究

介绍了特殊类型含硼金刚石的合成技术与特性.讨论了掺杂物含硼原料、合成工艺、实验条件对金刚石晶体生长的规律、性能和质量的影响,以及含硼金刚石合成机理和硼在合成中的作用.指出了进一步提高特殊类型含硼金刚石质量的方法与途径.     

含硼金属包覆膜的物相结构与含硼金刚石的生成

使用以FeB为硼源的含硼粉末冶金铁基触媒,在六面顶压机上高温高压合成含硼金刚石单晶.金相观察发现,金刚石金属包覆膜由粗大的板条状渗碳体和细密的莱氏体共晶组织构成.X射线衍射(XRD)发现,金属包覆膜的物相组成为(Fe,Ni)3C、(Fe,Ni)3(C,B)、石墨(Gr)以及γ-(Fe,Ni)(A).使用透射电镜(TEM)在包覆膜中发现了颗粒状的Fe3(C,B),条状的γ-(Fe,Ni) 和颗粒状的Fe23(C,B)6.电子探针分析(EPMA)结果表明,硼元素在包覆膜中存在浓度梯度,越接近含硼金刚石,硼元素的含量越高.分析认为,高温高压下硼是以铁-碳-硼化合物的形式通过金属包覆膜向金刚石晶体扩散的,Fe3(C,B)或(Fe,Ni)3(C,B)极有可能是含硼金刚石生长的直接碳源和硼源.     

用含硼T641石墨制造硼皮含氮人造金刚石的研究

介绍了用含硼Ｔ６４１ 石墨材料,研制硼皮含氮人造金刚石实验方法、条件、工艺及结果。讨论了影响硼皮含氮人造金刚石实验效果。硼在晶体中分布特征及其性质的因素。提出了进一步提高硼皮含氮金刚石质量的途径。     

含硼T641石墨合成金刚石的耐热性研究

本文介绍了含硼Ｔ６４１石墨合成金刚石具有耐热性高，抗氧化性好与化学惰性强的特性，根据实验结果讨论了含硼金刚石晶体氧化机理，而且指出了合成耐热性高，抗氧化性好和化学惰性强的优质金刚石的合成途径。     

关于人造含硼金刚石晶体结构及抗氧化性的研究

人造金刚石的抗氧化性是国际上评价其性能优劣的重要指标.文章以粉末铁基触媒中掺入不同含量的供硼剂为硼源,用静压法得到含硼量不同的人造金刚石.利用光学显微镜、X射线衍射仪和差热分析仪对含硼金刚石的晶形、晶体结构和抗氧化性能进行了研究,并与同样工艺条件下得到的普通金刚石进行对比,结果证明此种合成方法能够得到抗氧化性能优异的金刚石.     

高温高压Fe-Ni-C-B系中含硼金刚石单晶合成机理研究(下)

采用现代材料分析测试方法,通过对高温高压Fe-Ni-C-B系合成出的含硼金刚石单晶及其金属包覆膜进行系统分析和表征,探寻含硼金刚石合成机理及生长机制。研究发现,添加在金属触媒中的硼以金属-碳-硼化合物的形式溶入金属包覆膜,作为含硼金刚石生长的直接碳/硼源,经金属中间相的催化,析出活性碳/硼原子(团)扩散至正在生长的金刚石单晶表面,促进金刚石的生长。而含硼金刚石则以一种层状生长的方式长大,这种层状生长的台阶来源前期以二维晶核为主,后期则以位错为主。活性碳/硼原子(团)扩散到达金刚石单晶表面,在生长台阶的前端被吸附,转变成为金刚石单晶的一部分。随着台阶的不断扩展,新的生长台阶在刚长成的晶面上继续形成,含硼金刚石单晶则以层状堆叠的方式完成长大过程。     

渗硼石墨对人工合成金刚石性能的影响

石墨渗硼对合成金刚石性能影响的研究结果表明，采用渗硼石墨合成金刚石，可提高金刚石的粗颗粒百分比、抗压强度、热稳定性和单次合成产量，是一比较理想的合成金刚石的石墨材料。     

Study of chemical bonds in carbon and boron materials by EPMA

This paper describes the study of chemical bonds in carbon and boron materials (single-crystalline graphite, natural diamond, boron carbide and pure boron) by electron probe microanalysis. BK and CK X-ray emission spectra of the investigated materials are presented and discussed.     

碳热还原法制备碳化硼粉末的工艺研究

采用碳热还原法制备了碳化硼粉末样品,讨论了硼碳比、煅烧合成和粉碎过程等工艺参数对其粉末性能的影响。借助XRD分析手段测试了其成分,并用化学方法分析了粉末的总碳含量,用激光粒度分布仪测试了其粒度分布。实验结果表明:以工业用硼酸和炭黑为原料,在1700～1850℃、保温0.5～1h煅烧合成能制得纯度较高的碳化硼粉末。其总碳含量为20.7%,接近理论值。中位径为32.56μm,经球磨粉碎后,其中位径可以达到2.42μm。     

黑色含硼金刚石的合成

通过实验合成出了性质优异的黑色含硼金刚石,研究了合成条件、合成工艺对合成金刚石及其性质,以及晶体生长的影响。指出了进步提高金刚石质量的途径。     

铁基触媒合成金刚石形成的金属包膜成分的研究

利用电子探针(EPMA)和X射线光电子能谱(XPS)研究了包围金刚石单晶的铁基金属包膜和触媒的成分分布。结果表明,在金刚石生长过程中,接近金刚石单晶的包膜内层中的碳含量是变化的,但均高于接近金刚石的触媒层。然而,与包围金刚石单晶的触媒表面相比,包膜表面碳含量低、铁含量高。分析认为,高温高压下,金刚石生长的碳源主要来自于包膜,但碳并非均匀地在包膜熔体内层向金刚石扩散。结合前期研究发现的“包膜内层无石墨和无定形碳结构”的事实分析,金刚石生长所需的碳极有可能来源于包膜内层铁碳化物的瞬间分解,结果导致包膜表面瞬间碳含量低、铁含量高。     

Phase transformations in highly disperse powders during their rapid heating and cooling

Phase transformations in particles of ultrafine powders of graphite, hexagonal boron nitride, and quartz during rapid heating and cooling by passage through a laser beam were investigated. A continuous infrared laser with a wavelength of 10.6 μm was used as a heat source through which the powders were recycled several times. Methods of concentrating the product phases are described. Particles of diamond, carbides, cubic boron nitride, koesite and stishovite were obtained in the mixed products.     

The tribological performance of BCN films under ionic liquids lubrication

Boron carbon nitride films were deposited onto silicon substrates by medium frequency magnetron sputtering from graphite and boron targets with Ar and N₂ as feedstock. The three elements of B, C and N were bonded to each other and an atomic-level hybridized B–C–N had been formed in the films. The tribological performances of the boron carbon nitride film with 1-butyl, 3-methylimidazolium tetrafluoroborate ionic liquid as lubricant and the electrochemical corrosive behaviors of the BCN film were investigated. The boron carbon nitride film demonstrated excellent tribological properties and corrosion resistance as compared with diamond like carbon film. An extensive discussion of the effect of film intrinsically structure on both lubrication and corrosion under ionic liquid condition is given. In addition, the interrelation between the tribological properties and corrosion resistance is illustrated.     

Characterization of the condensed carbon in detonation soot

A number of pure and composite explosives with a negative oxygen balance were detonated in a hermetic steel chamber under different environmental conditions. After detonation, solid carbonaceous products (detonation soot) and ultrafine diamond separated from the soot were collected for examination. Elemental analysis, high resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier-IR, X-ray photoelectron spectroscopy and small angle X-ray scattering were used to characterize the structure, composition and surface properties of the condensed carbon in the soot. Crystallite size and microstrain of ultrafine diamond and the graphitization index of the graphite phase were calculated according to XRD patterns. The yields of the soot and ultrafine diamond from the explosives were obtained. The influences of charge conditions and environmental conditions on the formation mechanisms and properties of condensed carbon were analyzed. Detonation soot contains ultrafine diamond, graphite and amorphous carbon. Two types of graphite structures were present in the detonation soot.