超声波对润滑脂中固体添加剂分散作用的研究

研究了超声波对固体添加剂MoS2和WS2在复合磺酸钙基润滑脂中的分散作用.结果表明,超声波能在半熔体状态下的润滑脂中传播,并通过超声空化作用能较好地分散润滑脂中的固体添加剂微粒,提高润滑脂的抗磨性能.     

由钼酸钙制取二硫化钼

本文介绍了由钼酸钙和硫制取二硫化钼的方法、工艺条件,以及二硫化钼对润滑脂抗磨性能的改善情况。     

高温高转速低启动阻力全氟醚润滑脂

介绍了几种全氟醚(PFPE)的性能,测试了聚四氟乙烯微粉、二硫化钼填充全氟醚润滑脂的摩擦学性能,采用能谱仪对模拟台架试验后的磨屑进行成分分析。结果表明:随着聚四氟乙烯微粉含量的增加,全氟醚润滑脂的四球磨痕呈上升趋势;添加二硫化钼后,全氟醚润滑脂的摩擦因数降低。普通全氟醚润滑脂用于高速高温轴承时易导致干摩擦,内圈表面碳化;复配的全氟醚复合润滑脂具有耐热性和抗氧化性能优良、黏度适度、蒸汽压-温度特性良好、润滑性能优良、机械安定性好、启动力矩低,满足高温高转速低启动阻力工况条件的要求。     

部分润滑脂和金工油配方

下列配方实例中的配方量,均为重量份。 配方实例1:锂基润滑脂 2号 3号 大港10~#车用机油 1850 2300 十二羟基硬脂酸 126 192 硬脂酸 50 48 氢氧化锂 24 39 二苯胺 3 4 配方实例2:二硫化钼锂基脂 大港10~#车用机油 1850 2300 十二羟基硬脂酸 100 180 硬脂酸 20 48 氢氧化锂 14 49 二苯胺 6 7 二硫化钼 60 70 配方实例3:钠基润滑脂     

纳米坡缕石润滑脂添加剂工艺参数的优化

坡缕石可以改善润滑脂的摩擦学性能,文章采用超声波的分散方法将坡缕石添加到润滑脂中,其中坡缕石的含量、改性剂Kh550的百分比以及超声波的分散工艺参数等因素都将影响润滑脂的摩擦性能。本文以四球摩擦磨损实验的PB值为试验指标,利用正交试验的方法设计实验,并分析实验结果,对影响润滑脂摩擦学性能的主要因素进行优化设计。得到最佳的工艺参数:坡缕石的含量为2.0%、偶联剂Kh550的质量分数为1.0%、超声波的分散功率为180 W、分散时间为30 min。     

第十讲 机械设备的润滑（四）

从润滑剂的形态来看，有气体、液体、半固体及固体之分。常用的润滑油为矿物油、合成油，属液体类，也称稀油；常用的润滑脂为半固体塑性类润滑剂，也称干油；石墨、二硫化钼等粉状类为固体润滑剂。     

水泥厂实用机修技术(三十一)第十讲机械设备的润滑(四)

10.3润滑剂(上) 从润滑剂的形态来看,有气体、液体、半固体及固体之分.常用的润滑油为矿物油、合成油,属液体类,也称稀油;常用的润滑脂为半固体塑性类润滑剂,也称干油;石墨、二硫化钼等粉状类为固体润滑剂.     

用石墨粉作窑车的高温润滑剂

山东淄博电瓷厂100米隧道窑是用来烧成高压悬式电瓷,窑内高温带1300℃。全窑容纳窑车50部。过去采用二硫化钼润滑脂作为窑车轴承润滑剂,窑车高温带下部温度高达280～300℃。窑车轴承经过这样高温烘烤之后,其中二硫化钼润滑剂多半被烧焦变脆,几乎失去了润滑作用。如果每出一车都对轴承全部进行清理更新润滑剂,时间上来不及,只好注入气缸油再继续使用。这样,窑车变得十分笨重。为了改变这种状况,该厂从1978年8月开始试用一种无油高温润滑剂——石墨粉。     

一种快速溶解锂基润滑脂的方法研究

提出对锂基润滑脂的快速溶解方法是锂基润滑脂中皂基稠化剂的位于外部的烃基端第一次溶解,随后对皂基稠化剂的位于内部的羧基端进行第二次溶解.结果表明:有机溶剂溶解锂基润滑脂外部的烃基端,再加入不同比例的乙酸能快速溶解锂基润滑脂内部的羧基端,该方法简便、快速、实用、高效,不仅可以提高锂基润滑脂的溶解速度,提升样品的前处理效率,...     

二硫化钼润滑添加剂摩擦学性能研究现状

二硫化钼是具有良好润滑性能的六方晶层状物质。概述了二硫化钼作为润滑添加剂的摩擦学性能。二硫化钼在润滑油及其它润滑介质中均表现出良好的抗磨减摩性能。     

Comparative performance of impregnated molybdenum-sulphur catalysts in hydrogenation of Spanish lignite

Hydrogenation of a Spanish lignite of 12% sulphur content was conducted using three molybdenum-containing catalysts impregnated into the lignite: ammonium tetrathiomolybdate, a sulphided ammonium heptamolybdate, and molybdenum disulphide. The conversions to liquids and hydrodesulphurization were investigated for a series of residence times and temperatures. At 275 °C, the ammonium salts provide no greater conversion or sulphur removal than obtained in the absence of catalyst, because these salts have not decomposed to an active catalyst at this temperature. However, lignite impregnated with molybdenum disulphide does experience greater conversion and desulphurization than lignite reacted without catalyst. At 325 °C, the lignite impregnated with the ammonium salts gives conversions and desulphurization substantially superior to that achieved with molybdenum disulphide or without catalyst. This is attributed to the superior dispersion that can be achieved by impregnation using a solution of a soluble salt rather than a slurry of the insoluble disulphide. The best conversions, liquid yield, and desulphurization are achieved using impregnated sulphided ammonium heptamolybdate.     

Hydrocracking of a coal extract with various catalysts

Catalytic hydrogenations using a number of bimetallic and monometallic catalysts were performed in an autoclave fitted with a falling/spinning catalyst basket. The catalysts were used as oxides with and without the addition of carbon disulphide to the autoclave charge. The products were separated by vacuum distillation and the performance of the catalysts was assessed by combining the yields from vacuum distillation with the peak area distribution of the gas chromatographs of the distillation fractions. The presence of carbon disulphide reduced the yield of material boiling below 260 °C and was particularly effective in reducing the yield of material boiling below 175 °C. Bimetallic catalysts which included molybdenum as one component generally performed better than similar bimetallic catalysts which included tungsten as one component and better than monometallic catalysts. Commercial CoMo performed well both with and without added carbon disulphide but commercial NiMo was inferior to most other catalysts when carbon disulphide was not added and to many when carbon disulphide was added. The sulphur content of the liquid products was not significantly affected by the addition of carbon disulphide to the charge.     

Interaction of molecules with molybdenum disulphide catalysts: An experimental and molecular graphics study. Isoprene

The interaction of isoprene with molybdenum disulphide has been studied by computer-assisted modelling of the binding of the molecule at active sites. Possible structures of intermediate-active-site complexes were evaluated by the method of molecular mechanics. For isoprene hydrogenation the preferred catalytic sites, according to energy minimisation calculations, proved to be corner molybdenum atoms having threefold unsaturation. This conclusion agrees with deductions from experimental studies of isoprene hydrogenation. The modelling studies are valuable for revealing the steric relationships between active sites and substrate molecules, for calculating the most likely structures, and for revealing non-bonded interactions.     

原子吸收光谱法鉴别地沟油的方法探讨

由于地沟油中的成分比较复杂,含有食用油中没有的钠离子,通过超声萃取来进行处理,将油脂中具有代表性的钠离子萃取到去离子水中,然后通过原子吸收分光光度法对钠离子含量进行测定,并与食用油进行比较。实验证明,该方案可作为鉴别地沟油的方法之一。     

Influence of the nature of the activating molecules on the catalytic activity of cobalt—molybdenum/alumina catalysts

The effectiveness of the activation of a commercial CoMo/Al₂O₃ catalyst was evaluated using five different sulphiding agents (carbon disulphide, dimethyldisulphide, butanethiol, thiophene and hydrogen sulphide) at high pressure (3 MPa) in the 300–450°C temperature range. The results indicate that the behaviour of the cobalt—molybdenum catalysts depends strongly on the nature of the activating molecule as well as the pretreatment temperature. The catalyst exhibited two different patterns, below and above 400°C. At 300°C, differences in the degree of sulphidation and in activities were observed when using different activating molecules. The most efficient of the sulphiding agents used was butanethiol while the least efficient one was thiophene. The activity of the catalyst was a maximum when carbon disulphide was used at 350°C or the other sulphiding agents at 400°C. We attributed the differences of effects of the various molecules to coupling effects between reduction and sulphidation reactions. Under the activation giving excellent activities, the coupling effect is optimal. Using carbon disulphide or thiophene at temperatures higher than 400°C, a catalyst with strongly decreased activity was produced. This behaviour is attributed to coke formation during sulphidation.     

The observation of nanometer-sized entities in sulphided Mo-based catalysts on various supports

The progressive sulphidation of molybdenum-based hydrotreating model catalysts is studied using HRTEM and XPS. The catalysts are sulphided quasi in situ and prepared for TEM measurements in a glovebox. Subsequently, a specially developed vacuum-transfer specimen holder is used for transfer to the TEM. Using this procedure, a previously unknown feature is observed in the catalysts. Apart from the well-known slab-like structure of bulk molybdenum disulphide, nanometer-sized spherical entities of molybdenum sulphide or oxysulphide are observed. For a series of model CoMo/silica catalysts, these spots predominantly occur after mild sulphidation procedures. At higher sulphidation temperatures, these spots exist next to the slabs of MoS₂-like material. Comparison with practical molybdenum-based hydrotreating catalysts shows that these, too, can contain spots next to or instead of slabs, depending on precursor preparation and sulphidation procedures.     

Powder processing in a plasma jet: A proposed model

A theoretical study is reported on the use of d.c. and r.f. plasma jets as chemical reactors for the processing of minerals in the form of a fine powder. The temperature and flow fields of the jet are calculated by solving the integral boundary layer equations. Single particles trajectories are obtained by solving the Basset-Odar equations. A multi-particle model is then developed for a feed of known particle size and injection velocity distributions under low loading conditions. Calculators are made on the thermal decomposition of molybdenum disulphide (5 to 30-micron equivalent diameter). The parameters investigated are the free jet velocity, the mean injection velocity, and the reactor ambient conditions. The results are presented as the probability density distributions of the gas loading, particle temperature, and conversion at different levels downstream of the nozzle.     

润滑脂流变性影响因素研究现状

润滑脂由于其复杂而独特的流变性能,近年来受到了学界的广泛关注。学者们选用一系列流变参数来定性定量描述润滑脂的流变性能。润滑脂组分、工作条件及制备手段的变化常常会影响和改变润滑脂的流变参数。综述了温度,稠化剂结构、含量及粒度,基础油,添加剂及填料,制备条件,微观结构等因素对润滑脂流变参数的影响情况,总结了润滑脂流变学发展中存在的问题,并对润滑脂流变学未来的发展进行了展望。     

复合锂基润滑脂的研究进展

复合锂基润滑脂具有良好的高温多效性能,自发明以来持续受到广泛研究和应用.同时复合锂皂良好的基础油稠化能力和添加剂感受性,使其可以制备满足各种工况要求的润滑脂.综述了复合锂基脂组成和制备工艺对其性能及结构的影响,探讨了复合锂基脂成脂机理,并对复合锂基润滑脂的未来发展进行了展望.