粉末触媒、石墨配比对合成金刚石质量的影响

将不同配比的Fe70Ni30粉末触媒与石墨混合压制成粉末触媒合成棒,在国产六面顶压机上进行金刚石高温高压合成实验,并对合成的金刚石单产、粒度分布、晶形、抗压强度值、TI、TTI值进行了对比测试与观察分析.结果表明,对Fe70Ni30粉末触媒合成棒而言,当合成棒中Fe70Ni30粉末触媒含量为30%时合成金刚石的单产达到最大值,金刚石的TI、TTI值较高且TI/TTI差值最小,热冲击韧性最好.     

合成柱密度及触媒参数对自锐性金刚石的影响

利用水雾化Fe70Ni30合金粉或FeMn合金粉与石墨混合原料,经过还原与净化处理,造粒并压制成合成柱,用于自锐性金刚石的合成,研究了粉末触媒的粒度、含氧量、触媒与石墨的配比以及合成柱的压制密度等工艺条件对合成自锐性金刚石粒度和形貌、单次产量以及冲击韧性等的影响。结果表明,触媒的含氧量对合成后金刚石的形貌有明显影响,合成自锐性金刚石时控制触媒的含氧量在0.08%～0.1%wt为佳;合成柱中触媒的含量越高,金刚石单次产量越高,合成柱中触媒含量在30%wt左右时所获得金刚石的TI值达到最大;随着合成柱密度的提高,金刚石的合成单次产量明显提高,金刚石的冲击韧性TI值也稍有提高。     

粉末触媒对合成金刚石质量的影响

将具有不同氧含量、镍含量、粒度分布的粉末触媒与石墨粉按照一定比例混合压制成合成棒,在国产六面顶压机上进行金刚石高温高压合成实验,并对合成的金刚石单产、颜色、粒度分布、TI、TTI值进行了对比分析。结果表明:以氧含量低、镍含量适中、粒度细且集中的粉末触媒为原料,合成的金刚石整体质量较好。     

气雾化FeNi粉末触媒及合成金刚石的特性

文章主要介绍了气雾化方法制备FeNi粉末触媒的物理特性、显微组织结构和一200目FeNi粉末触媒的粒度组成．利用-200目FeNi粉末触媒合成的金刚石大多为六一八面体，晶型完整，颜色金黄，包裹体少，其TI和TTI（1100℃）性能良好。     

粉末触媒法SSD金刚石的合成及磨削应用

利用水雾化Fe70Ni30合金粉或Fe70Mn25Ni5合金粉与石墨原料混合,经过还原与净化处理、造粒和压制成合成柱,用于自锐性金刚石(Self Sharpening Diamond,SSD)的合成,研究了粉末触媒法自锐性金刚石的合成工艺条件。研究结果表明,不同触媒组分对合成后金刚石的形貌有明显影响;根据优化的SSD合成工艺参数,可以稳定自锐性金刚石单次产量在90ct以上。用SSD金刚石制成树脂结合剂砂轮应用于磨削时磨削力小,粗糙度低。     

Fe基合金/石墨系柱状金刚石的高温高压合成与表征

用国产SPD 6×1200型六面顶压机,在10%Fe/90%Fe70Ni30粉末触媒和石墨（Fe–C）体系中,在压力为5.0～5.5 GPa、温度为1 550～1 600 K下合成出柱状金刚石晶体。研究了晶体的形态和生长习性。结果表明：合成的柱状金刚石晶体的颜色呈现绿色,晶体的长度为0.6～0.8 mm,长径比约为2....     

高温高压下用氧化硼添加剂合成金刚石

文章研究了氧化硼添加剂对Fe70Ni30触媒合成金刚石的影响。当前掺硼金刚石是研究的热点，但关于利用Fe70Ni30触媒合成掺氧化硼的金刚石的文章却不多。在实验中将一定比例的氧化硼添加到石墨Fe70Ni30粉束体系中并混合均匀，在六面顶压机上利用高温高压合成掺氧化硼金刚石。实验结果表明，添加一定量的氧化硼对金刚石的合成压力和温度的影响不大，但掺氧化硼合成的金刚石与不掺杂合成的金刚石在颜色和表面形貌上有很大的区别。对这种情况作了比较和分析。     

Ni-Fe-RE-C粉末一体化金刚石合成工艺研究

粉末触媒-石墨和片状触媒-石墨存在着较大的物理差异，如粉末触媒比表面积比片状触媒大几十倍，因此，金刚石在粉末触媒表面上形核数目大大增加，并能在各个方向均匀发育，合成金刚石的单产量大幅度提高，且晶体的晶形更趋完整。用粉末触媒合成金刚石与片状触媒合成金刚石既有相似的地方，也有不同之处，关键在于怎么控制金刚石的形核与生长。合成锯片级完整六一八面体金刚石，腔体高温／高压必须进入一个非常小的区域，如果处于较大区域间，则将会出现多种类型的金刚石，使生长条件变化。问题是如何进入这一特定的区，避免通过所不期望的区域。     

铁基触媒合成金刚石形成的金属包膜的组织结构

利用SEM，TEM和Raman光谱检测手段，研究了铁基触媒合成金刚石形成的金属包膜的组织结构。结果表明：包膜与合成后触媒的组织形貌不完全相同，包膜内无金刚石，在靠近金刚石的包膜内层没有石墨和无定型碳。据此并结合包膜所起的溶碳和催化作用分析，在高温高压下，金刚石成核和生长的碳来源于靠近金刚石的包膜层(Fe，Ni)3C的分解产物，分解后的(Fe，Ni)3C转变为γ—(Fe，Ni)，这时的γ—(Fe，Ni)与末分解的(Fe，Ni)3C保持晶面平行关系。     

铁基触媒合成工业金刚石中包裹体研究

借助穆斯堡尔谱的测试方法,对不同铁基粉末触媒合成的工业金刚石中的包裹体进行了检测,结果表明,纯Fe触媒合成的金刚石晶体中的包裹体为α-Fe和Fe3C;Fe90Nil10和Fe80Ni20合成的金刚石晶体中的包裹体主要以FeNi合金和Fe3C形式存在,同时随着触媒中的Fe含量的降低,包裹体Fe3C的相对含量随之降低.另外,对包裹体的形成机制进行了分析.通过对包裹体的成分和形成机制的研究,提出了有效减少金刚石中包裹体的方法.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。