可生物降解润滑油新型抗氧剂研究

新型环保型抗氧剂迷叠香是从云南一种天然植物中提炼而成,可降解、抗氧化性能好.使用抗氧剂迷叠香与传统抗氧剂T501进行复配,采用旋转氧弹法对该类新型抗氧剂抗氧化安定性进行了测试,发现其有很好的抗氧化效果,较单独使用T501抗氧化效果有很大改善.通过合理选择基础油配制方式及比例,结果表明:当在基础油(菜籽油、季戊四醇酯和聚α烯烃的比例为15:3:2)中添加抗氧剂T501与迷叠香各0.5%(质量分数)时氧化时间最长.     

PDSC法研究煤转化基础油的氧化安定性

用加压差示扫描量热法(PDSC)研究了煤转化的基础油(CTL)和Ⅲ类油以及Ⅳ类油(PAO)的氧化安定性,并考察了3种基础油对抗氧剂的感受性.结果表明CTL基础油的氧化安定性和Ⅲ类油接近,但是比Ⅳ类差.3种基础油对胺类抗氧剂(AO)的感受性相近,但Ⅳ类油的感受性最好.由煤转化而成的CTL基础油有可能成为Ⅲ类基础油的替代品.     

加氢异构基础油的氧化安定性研究

选用几种加氢异构化的基础油作为试验原料,采用核磁共振波谱法分析其烃类结构组成;利用加压差示扫描量热法(PDSC)研究基础油的异构化程度与氧化安定性的关系,考察异构化基础油对抗氧剂的感受性。结果表明,异构化程度高的基础油氧化安定性较好,对抗氧剂的感受性也较好。     

DOI:10.3969/j.issn.0254-0150.2012.08.023

选用几种加氢异构化的基础油作为试验原料,采用核磁共振波谱法分析其烃类结构组成;利用加压差示扫描量热法(PDSC)研究基础油的异构化程度与氧化安定性的关系,考察异构化基础油对抗氧剂的感受性.结果表明,异构化程度高的基础油氧化安定性较好,对抗氧剂的感受性也较好.     

基于PDSC程序升温法的抗氧剂氧化能力评价

提出一种基于PDSC（高压差示扫描量热）程序升温法的抗氧剂的性能评定及筛选方法。利用PDSC程序升温法,测定不同升温速率下添加不同抗氧剂的基础油的氧化峰峰顶温度,采用Ozawa Flynn wall 法与Kissinger法计算氧化反应的动力学参数,对几种胺型和酚型抗氧剂的抗氧化能力进行评价。结果表明,PDSC程序升温法可以用于评价抗氧剂的抗氧化能力; 胺型抗氧剂可以降低油品活化能,适合做高温抗氧剂,酚型抗氧剂可以提高油品的活化能,适合做低温抗氧剂。     

酯类基础油的热氧化与水解稳定性能研究

热氧化和水解是造成酯类合成油衰变的最重要原因,也是影响酯类基础油的有效使用寿命的关键因素。在恒温箱中对3种酯类基础油进行连续老化试验,考察其在在无水、有水(铜片作为催化剂)以及有添加剂存在条件下的运动黏度和总酸值的变化,并结合差示扫描量热法(DSC)所测得的起始氧化温度,比较酯类油的热氧化、水解情况以及抗氧剂对酯类基础油老化过程的影响。试验结果表明:酯类基础油的热氧化稳定性与其自身分子结构有关,含有芳烃或合成的醇类结构中不含β-H的基础油会具有较好的热稳定性。酚类和胺类抗氧剂能有效地抑制不饱和多元醇酯类基础油的热氧化速度,起到较明显的抗氧化作用,并具有一定的抑制基础油水解的效果。     

酯类航空润滑油热氧化安定性评价方法研究

采用差示扫描量热法(DSC)对经过不同温度、不同时间反应后的航空润滑油基础油癸二酸二-2-乙基己酯(DIOS)、50-1-4φ航空润滑油及加入抗氧剂的基础油进行动态和静态氧化试验,通过分析处理热流曲线,分别得到不同油样的起始氧化温度(IOT)和氧化诱导期(OIT),并对添加抗氧剂前后油样的氧化安定性进行评价。结果表明:3种油样的IOT值与OIT值分别处于206~255℃和12~31 min的范围内,且随着初始反应温度的增加和反应时间的延长,油样IOT值与OIT值都呈先减小后增大再减小的总体下降趋势,表明在更高温度、更长时间下反应后,油样的氧化安定性会变差;油品的OIT值变化规律与IOT值的相同,表明采用这2种指标来评价油样的氧化安定性结果基本一致;添加抗氧剂后的基础油油样的IOT值均呈增大趋势,表明该抗氧剂可提升基础油的氧化安定性,而对于成品油50-1-4φ,由于多种添加剂的协同作用效果,相比单一添加抗氧剂,油品的氧化安定性得到了进一步提高。     

二丁基二硫代氨基甲酸铋的抗氧协同性能

为研究有机铋添加剂的抗氧化性能及与传统抗氧剂复配后的抗氧协同作用,采用薄层油膜微氧化实验考察二丁基二硫代氨基甲酸铋(Bi DDC)与p,p-二异辛基二苯胺(DODPA)在聚-α-烯烃(PAO)合成基础油和150SN矿物基础油中的抗氧协同作用,借助红外光谱定量分析基础油在不同氧化时间下的氧化程度,探讨Bi DDC与DODPA的抗氧协同机制。结果表明:Bi DDC自身具有一定的抗氧化性能,与DODPA复配后,Bi DDC可以起到消除自由基和分解氢过氧化物的作用,可使润滑油中的氢过氧化物分解,而芳胺抗氧剂能够捕捉自由基,控制氧化链的生长;Bi DDC和DODPA复配后,能够降低添加剂的用量,提升润滑油的抗氧化能力,表现出了良好的抗氧协同性能。     

自动传动液的摩擦特性研究

使用SAE№2试验机进行自动传动液(ATF)的摩擦特性研究,探讨基础油、添加剂对其摩擦特性的影响规律.试验结果表明,基础油中的饱和烃含量决定基础油的摩擦耐久性,饱和烃含量越高,摩擦耐久性越好,基础油中微量的含硫化合物影响基础油的高温摩擦特性,同时高钙含量的清净剂可以提高基础油的摩擦耐久性.除防锈剂外,其它添加剂如抗氧剂、抗磨剂、金属钝化剂等对基础油的摩擦特性均有不良影响.     

苯酚类、苯胺类和硫醚类抗氧剂对动物性油脂的氧化防护效果与评价

为评价常用抗氧剂在金属加工用油产品中的抗氧化效果,选取动物性油脂(精炼猪油)为基础油,运用热重分析法(TGA)和高压差示扫描量热法(PDSC),并结合老化实验,分别考察3类共4种抗氧剂在不同温度下对该基础油的氧化防护效果。实验结果表明,抗氧剂能够有效防止油品氧化,但不同类型抗氧剂的抗氧化效果存在明显的差异;较低温度下,苯酚类抗氧剂优于苯胺类和硫醚类抗氧剂,而硫醚类抗氧剂在高温下的氧化防护性能更优异;为有效地保护油品,在实际应用中,需要将不同类型的抗氧剂进行复配,取长补短,以适应更广泛的工况条件。     

S-N型润滑添加剂的合成及其摩擦学性能研究

合成一种新型环境友好型、无灰、非磷极压抗磨剂——含羟基二烷基二硫代氨基甲酸衍生物(DDCSD)。采用红外光谱仪对其结构进行表征,利用热分析仪考察其热稳定性,使用四球试验机及SRV考察其在复合锂基润滑脂中的摩擦学性能,并用扫描电子显微镜及X射线光电子能谱分析摩擦表面形貌及表面化学成分。结果表明,DDCSD具有良好的热稳定性,能有效提高基础脂的抗磨、减摩及极压性能,可作为多功能润滑油脂添加剂ZDDP的替代品。这是由于DDCSD在摩擦过程中发生化学吸附及摩擦化学反应,在金属表面上形成了一层具有抗磨减摩性能的边界润滑膜,从而起到抗磨减摩的作用。     

Friction torque in grease lubricated thrust ball bearings

Thrust ball bearings lubricated with several different greases were tested on a modified Four-Ball Machine, where the Four-Ball arrangement was replaced by a bearing assembly. The friction torque and operating temperatures in a thrust ball bearing were measured during the tests. At the end of each test a grease sample was analyzed through ferrographic techniques in order to quantify and evaluate bearing wear.A rolling bearing friction torque model was used and the coefficient of friction in full film lubrication was determined for each grease, depending on the operating conditions.The experimental results obtained showed that grease formulation had a very significant influence on friction torque and operating temperature. The friction torque depends on the viscosity of the grease base oil, on its nature (mineral, ester, PAO, etc.), on the coefficient of friction in full film conditions, but also on the interaction between grease thickener and base oil, which affected contact replenishment and contact starvation, and thus influenced the friction torque.     

石墨烯作为轧钢机轴承润滑脂添加剂的研究*

为改善轧钢机轴承用润滑脂的性能,采用不同质量分数的石墨烯对润滑脂进行了改性,测定各润滑脂样品的锥入度和滴点,使用四球摩擦试验机研究石墨烯对润滑脂摩擦学性能的影响,使用扫描电子显微镜、白光干涉仪和拉曼光谱仪等分析石墨烯在润滑脂中的减摩抗磨机制。结果表明:石墨烯作为添加剂能提高润滑脂的滴点和改善润滑脂的极压性能以及减摩抗磨性能。当石墨烯质量分数为0.2%时,对润滑脂极压性能的提升效果最好,表现为烧结负荷和综合磨损值最大,较基础脂分别提高了29.0%和24.0%;当石墨烯质量分数为0.3%时,对润滑脂减摩抗磨性能的提升效果最好,摩擦因数和磨斑直径较基础脂润滑时分别下降了22.4%和13.0%,磨损体积减少了43.0%,且最大无卡咬负荷提高了21.2%。石墨烯在摩擦过程中,吸附在摩擦表面,形成保护薄膜阻止了摩擦副材料的直接接触,减少了磨损,同时提高了润滑脂的承载能力。     

高低温性能优良的膨润土润滑脂的研制

以季铵盐改性膨润土为稠化剂,酯类油为基础油,乙醇为助分散剂,添加极压、抗磨、防腐、抗氧等添加剂,制备一种高、低温条件下性能优良的膨润土润滑脂.用扫描电子显微镜观察脂的微观结构,研究助分散剂对脂结构及脂稠度的影响.各项性能测试结果表明:制备的膨润土润滑脂具有良好的低温性能、胶体安定性、氧化安定性、防腐性和极压抗磨性.     

润滑剂对轮轨摩擦与磨损的影响

利用MMS-2A磨损试验机模拟轮轨系统在润滑油、二硫化钼锂基脂、植物油和石墨钙基脂4种润滑剂润滑下的摩擦与磨损行为,研究润滑剂对轮轨副摩擦、磨损特性的影响.结果表明:与干态相比,4种润滑剂均使摩擦副的摩擦因数减小,表面磨痕深度减小,磨损量降低,其中石墨钙基脂的减摩和抗磨效果最好;试验结束后,轮轨试样接触表面的硬度均有不同程度的增加,其中涂有石墨钙基脂的轮轨试样的表面硬度增加最小.     

锂基润滑脂FE9寿命的影响因素探讨

介绍了滚动轴承润滑脂测试仪FE9的测试条件及测试润滑脂寿命的重要意义,并以锂基润滑脂为研究对象,探讨油分离度和极压抗磨性对润滑脂寿命的影响,试验结果表明:锂基润滑脂油分离度过大或过小都会影响润滑脂寿命,合理选择锂基润滑脂极压添加剂不仅可以提高润滑脂寿命,而且可以使轴承运转更平稳.     

The Slow-Speed Wear Behavior of Case-Carburized Gears Lubricated with NLGI 00 Grease under Boundary Lubrication Conditions

NLGI 00 greases are often used to lubricate gears running at low pitch line velocities, such as, for example, in large open gear drives. At low pitch line velocities, sliding wear, which under these operating conditions is referred to as slow speed wear, is often the limiting factor to gear lifetime. A thorough knowledge of the effect of different grease components on the wear behavior is therefore important when selecting a grease to effectively reduce gear wear in a given gear drive. In order to systematically investigate and analyze the influence of different grease components on the slow-speed wear behavior of case-carburized gears, systematic gear tests using the Gear Research Center's (FZG) back-to-back gear test rig were conducted. Primarily, the focus of the experimental investigations is on the influence of the base oil viscosity and type, the additive type, and also the type of soap thickener on the gear wear behavior at low pitch line velocities. To experimentally determine the influence of these different grease components on the wear behavior of case-carburized gears, a modified, more stringent wear test, based on the standard DGMK slow-speed wear test for gear oils, was developed. Different NLGI 00 greases with base oil viscosities between ν₄₀ = 70 and 1,200 mm²/s were investigated.

Base oil type and base oil viscosity were shown to have only a minor effect on the wear behavior under boundary lubrication conditions. On the other hand, the thickener type and especially the additive type play an important role in determining the wear behavior.     

The effect of gear oil viscosity and friction reducer type on transmission efficiency

The effects of gear oil viscosity and friction reducer type on transmission efficiency have been investigated using the manual transmission and hypoid rear axle of a typical Japanese car. A reduction in the viscosity of the oil improved the efficiency of the manual transmission but led to positive and negative effects in the rear axle, depending upon operating conditions. The effect of the friction reducer varied according to the type of EP additive used, indicating the necessity of preliminary investigations of compatibility with EP additives before adding friction reducers to gear oils.     

富勒烯与纳米二硫化钨极压抗磨协同性能研究

为探讨富勒烯与纳米二硫化钨的极压抗磨协同性能,利用四球试验机考察富勒烯与纳米二硫化钨复配后在PAO基础油中的摩擦学性能;采用扫描电子显微镜对试验钢球磨痕形貌进行分析,探究富勒烯与纳米二硫化钨的协同作用机制。结果表明:富勒烯与纳米二硫化钨单剂对PAO基础油减摩抗磨效果的改善不明显,而富勒烯与纳米二硫化钨复配后可明显提高油样的减摩抗磨性能,其中质量分数0.01%富勒烯与0.005%二硫化钨复配后减摩抗磨协同效果最优,这是因为富勒烯能够实现滚动摩擦,而纳米二硫化钨能够沉淀到磨损处,起到修复的作用,两者的协同作用,提高了基础油的抗磨减摩性能;富勒烯与纳米二硫化钨复配并不能提高基础油极压性能,这是因为富勒烯不能与纳米二硫化钨生成新的物质来提高基础油的承载能力。     

Frictional performance of lithium 12‐hydroxystearate greases with different soap fibre structures in sliding contacts

The effect of the fibre structure of the grease on the frictional performance of lithium 12‐hydroxystearate greases with different fibre lengths was investigated in face, line, and point contact sliding tests. At high sliding speeds where the lubrication regime was practically hydrodynamic, the coefficient of friction of the base oil alone was lower than that of the greases. The coefficient of friction was roughly estimated as follows: base oil < long‐fibre grease < medium‐fibre grease < short‐fibre grease. The supply or replenishing capability of the grease played a critical role in maintaining hydrodynamic lubrication. At high contact pressures, the short‐fibre grease was superior in frictional performance to the long‐fibre grease due to the firm fibre network structure of the latter. In mixed and boundary lubrication regimes, the greases were superior in frictional performance to the base oil, since the soap fibres of the greases had a superior load‐carrying capacity. The long‐fibre grease, with a firm fibre structure, offered better frictional performance than the short‐fibre one.