二硫化钼固体润滑性能及其应用

详细介绍了二硫化钼的结构特点以及作为固体润滑减磨材料的原理.综述了二硫化钼作为固体润滑的粘结型固体润滑膜、沉积型固体润滑膜这两种固体润滑膜的性能及工艺特点,并介绍了它们在工业上的应用及其发展现状.     

关节轴承固体润滑处理工艺

介绍一种关节轴承固体润滑处理技术,制备的固体润滑膜以无机盐和活性金属离子为黏结剂,提高了膜层的耐压强度和耐温性能;以石墨和二硫化钼复合材料为润滑剂,提高了关节轴承在不同工况条件下的承载能力和润滑性。经固体润滑处理的轴承内圈外表面润滑膜层均匀、外观细致,实际使用效果良好。经检测,形成的固体润滑膜与金属基体有较强的结合力,在特殊工况条件下能够满足承载和润滑性能的要求。     

风电绝缘轴承表面防护膜的制备及其绝缘性能分析

为提高风电绝缘轴承的力学性能和绝缘性能，延长其在复杂工况下的服役寿命，提出采用磁控溅射法在绝缘轴承陶瓷涂层表面沉积镍膜。通过设计正交试验分析了靶电流、负偏压、溅射时间对镍膜表面形貌的影响以及镀膜对绝缘涂层表面粗糙度的影响，结果表明：随靶电流和负偏压增大，镍膜表面质量提高；溅射时间对镍膜表面质量影响较小，但会影响镍膜厚度；镀膜后表面粗糙度值降低；在靶电流为4 A,负偏压为300 V,溅射时间为90 min时镍膜表面光滑平整，连续性以及膜层致密性最优，为最佳工艺参数。在某风电轴承外表面制备镍膜后，交流击穿电压由6 100 V提高至6 300 V,直流电阻由23 GΩ提高至95 GΩ,绝缘性能提高，说明该工艺的正确性。     

Ti/TiN复合膜工艺优化及性能研究

利用正交试验和极差分析方法，分析了多弧离子镀Ti／TiN复合膜中工艺参数（弧电流、氮气分压、基体负偏压、钛过渡层厚度）对Ti／TiN复合膜的纳米硬度和膜与基体的结合力的影响及主次关系，并通过正交试验对工艺参数进行了优化。研究表明，氮气分压和弧电流是影响Ti／TiN复合膜纳米硬度的2个最主要因素，膜层与基体的结合力随着弧电流的增加而下降；升高基体负偏压，虽然可以提高Ti／TiN复合膜纳米硬度和膜与基体的结合力，但是高负偏压将急剧升高基体温度，可能导致基体退火；沉积一定厚度的钛过渡层可以显著提高TiN膜层与基体的结合力。     

表面织构对二硫化钼喷涂膜摩擦学性能的影响研究

在试件表面激光加工表面织构,采用喷涂法制备二硫化钼固体润滑膜,在环块摩擦磨损试验机上研究沟槽型表面织构对二硫化钼固体润滑膜的摩擦学性能的影响。结果表明,在一定的工况条件下,就固体润滑膜的寿命而言,微沟槽的几何参数存在最优值。分析发现,织构可以储存固体润滑剂,在一定的工况条件下,会使得织构内的固体润滑剂被挤出,不断地补充摩擦接触面间的固体润滑剂,使得固体润滑膜的寿命延长。     

表面织构对二硫化钼喷涂膜摩擦学性能的影响

在试件表面激光加工表面织构,采用喷涂法制备二硫化钼固体润滑膜,在环块摩擦磨损试验机上研究沟槽型表面织构对二硫化钼固体润滑膜的摩擦学性能的影响。结果表明,在一定的工况条件下,就固体润滑膜的寿命而言,微沟槽的几何参数存在最优值。分析发现,织构可以储存固体润滑剂,在一定的工况条件下,会使得织构内的固体润滑剂被挤出,不断地补充摩擦接触面间的固体润滑剂,使得固体润滑膜的寿命延长。     

固体润滑剂MoS2溅射技术

本文讨论目前应用广泛的溅射工艺,特别是应用于沉积MoS2、WS和PTFE固体润滑的溅射技术.溅射MoS2膜试验结果表明,固体润滑特性直接受选择的溅射参数(功率、密度、压力、溅射蚀刻、直流偏压等)和底材温度、表面化学性质、外形以及摩擦试验时环境条件的影响.电子显微镜和其他表面灵敏的分析手段表明,溅射MoS2膜的形态和化学性质的组合变化直接影响膜的结合强度和摩擦性质,薄的溅射润滑膜只有在选择了合适的溅射参数和被镀工件的材料时,才能可靠使用.附图1幅,参考文献2篇.     

二硫化钼涂层制备方法研究

选用电泳沉积法、刷涂法和水煮法3种方法在材料表面制备了二硫化钼涂层,并探讨了3种方法形成涂层的机制.结果表明,电泳沉积法、水煮法和刷涂法都可以得到很好的二硫化钼固体润滑膜,其中电泳沉积法制备的涂层的结合强度最大,表面硬度最高;3种制备方法都主要以机械结合方式形成涂层.     

IBAD制备WS_2-Ag固体润滑膜长期存储后的摩擦磨损性能

采用离子束辅助沉积技术在9Cr18轴承钢材料上制备掺杂Ag的WS_2固体润滑膜,并将该膜层在室内环境(温度为18~25℃,空气相对湿度为30%~50%)中保存8年。通过摩擦磨损试验机(MS-T3000)、场发射扫描电子显微镜、三维形貌仪及XPS检测保存前、后的WS_2-Ag固体润滑膜样品的摩擦磨损、表面形貌、三维形貌、成分及化学态。结果显示:贮存后的WS_2-Ag膜层内部氧含量的增加,膜层中Ag元素和少量W元素的氧化,以及S元素的损失,导致膜层摩擦磨损磨痕形貌出现了层状或者块状剥落;贮存后的WS_2-Ag复合固体润滑膜耐磨寿命有较贮存前的250 min缩短了103 min,仍然具有较好的固体润滑性能,其中Ag掺杂抑制了WS_2的潮解,提高了其抗氧化性能,大幅度延长了固体润滑膜的性能和寿命。     

高速低温轴承复合沉积膜设计分析

分析了高速低温轴承的工况,确定了采用离子束辅助沉积法进行表面改性,并选择WS2作为固体润滑膜。通过对试样进行膜层性能检测及结果分析可知,采用离子束辅助沉积技术在内、外圈滚道上沉积WS2固体润滑膜的方案可行。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

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.     

Non-monotonic material contrast in scanning ion and scanning electron images

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.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

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...     

分布动态载荷识别的抗噪处理

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.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

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....     

The laboratory simulation of abrasive wear

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

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.