共查询到20条相似文献,搜索用时 93 毫秒
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用油膜承载能力及四球机试验等方法极压抗磨性能,以硫磷型极压抗磨剂和油性剂等为主剂进行复配,对油品配方研究及解决极压抗磨性能打下了基础,。产品轻工业现场使用试验证明,极压抗磨性能完全能够满足设备的使用要求。 相似文献
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金属冷塑成型用润滑剂研究 总被引:3,自引:0,他引:3
研究了蓖麻油加入二硫化钼、铝粉、石墨等添加剂后摩擦磨损性能以及极压性能的变化。用四球摩擦磨损试验机进行对比实验,研究了二硫化钼、铝粉、石墨、磁流体对摩擦因数、磨损的影响。结果表明:(1)蓖麻油为基础油,添加二硫化钼等添加剂,能提高蓖麻油的减摩、抗磨和极压性能。(2)含MoS210 g/L,A l粉30 g/L,石墨50 g/L的蓖麻油其减摩、抗磨和极压性能最好。(3)二硫化钼能起到极压添加剂的作用;A l粉能提高润滑油的稳定性;石墨含量是影响润滑剂摩擦因数最主要因素。 相似文献
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为提高环境友好型润滑油极压抗磨添加剂三嗪衍生物的水溶性,将水溶性和防锈性良好的官能团磺酸盐引入三嗪衍生物,合成2种含磺酸盐的三嗪衍生物STB和STC,并评价其在水-乙二醇难燃液压液(HFC)中的理化性能和摩擦学性能。结果表明:STB和STC水基润滑添加剂在HFC中能够起到很好的极压抗磨减摩作用,其中质量分数2%STB和1%STC可使HFC的极压值提高到696 N,相比基础油液的极压值提高了109%。SEM和XPS分析结果表明,添加剂在摩擦过程中发生了化学反应,生成了无机硫化物和有机氮等组成的复杂边界润滑膜,从而起到了良好的抗磨减摩作用。 相似文献
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纳米Al/Sn金属颗粒对润滑油抗磨极压性能的影响 总被引:6,自引:2,他引:6
利用四球试验机分别对添加有纳米铅粉、锡粉以及Al Sn金属粉的润滑油进行极压和抗磨性能实验。采用SEM(扫描电子显微镜)对摩擦表面进行观察,采用EDS(能量色散谱仪)对表面进行元素测定。测试结果表明.纳米Al Sn金属粉可在较宽的载荷范围内明显改善润滑油的极压抗磨性能。其作用机理是锡粉在低载荷阶段沉积到摩擦表面起到抗磨剂作用,铝粉在高载荷阶段沉积到摩擦表面起到极压剂作用.从而实现了在低载荷到高载荷范围内对润滑油抗磨极压性能的提高. 相似文献
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极压抗磨剂对复合锂钙基润滑脂性能及结构的影响 总被引:2,自引:0,他引:2
通过复合锂钙基润滑脂在加入极压抗磨添加剂前后的性能及结构变化,研究了极压抗磨剂对润滑脂的影响。结果表明:在标准实验条件下,极压抗磨剂磷酸三甲酚酯(T306)、二烷基二硫代磷酸锌(T202)、二丁基二硫代氨基甲酸钼(T351)、硫化异丁烯(T321)、硼酸钠(T361)等组合可大幅提高润滑脂的极压抗磨性能,对结构及其它性能无明显影响;在加水10%剪切10万次条件下,含上述极压抗磨剂组合的润滑脂的结构及性能变化比较明显,其复合结构被破坏,滴点大幅下降,含T361的脂极压性下降最多;经过高温后(180℃,24 h)含上述极压抗磨剂组合的润滑脂,能保持或提高原有的极压抗磨性,润滑脂的复合结构没有明显改变,润滑脂的稠化剂纤维结构破坏较大,一般会造成润滑脂的硬化。 相似文献
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为研究新型油溶性稀土极压抗磨添加剂二烷基二硫代氨基甲酸镧(LaDTCs)的结构与性能关系,合成了9种含不同碳原子数的伯、仲烷基LaDTCs.利用四球试验机考察了其在500SN基础油中的摩擦磨损性能和极压性能,并探讨了烷基碳链的长短和伯、仲烷基结构对LaDTCs性能的影响.结果表明,含2~8碳烷基的LaDTCs均具有较好的抗磨减摩性能和极压性能.随着碳原子数的增加,LaDTCs的摩擦学性能明显提高,其中伯烷基LaDTCs的抗磨减摩性能优于仲烷基LaDTCs;含仲烷基的LaDTCs极压性能优于含伯烷基的LaDTCs. 相似文献
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Clarence W.DE SILVA 《Instrumentation》2019,(4):72-84
An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t... 相似文献
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INTEGRAL EQUATION METHOD'S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES 总被引:1,自引:0,他引:1
LI Cheng ZHENG Yanping 《机械工程学报(英文版)》2008,21(6):115-118
The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value. 相似文献
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30 keV Ga+ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z2, and shows a non-monotonic relationship between contrast and Z2. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z2, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory. 相似文献
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This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an... 相似文献
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分布动态载荷识别的抗噪处理 总被引:2,自引:2,他引:0
针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性. 相似文献
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针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。 相似文献
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The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar... 相似文献
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The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods.... 相似文献
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J. A. Williams 《Lubrication Science》1997,3(3):267-306
Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface. 相似文献
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M. Stedman 《Journal of microscopy》1988,152(3):611-618
Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space. 相似文献