发动机润滑油使用中的组成变化和性能衰变特性

以市售全合成发动机润滑油为研究对象, 通过实车运行10 000 km, 研究润滑油使用过程中的性能及组成变化, 并探究其衰变特性。研究结果表明: 润滑油使用后运动黏度降低23.84%;总酸值和正戊烷不溶物增至3.53 mg/g和0.268%;磨损元素Fe、Al和污染物元素Si的量分别由＜1、＜1和2 μg/g增加至11、20和20 μg/g; 润滑油衰变过程中聚α烯烃(PAO)发生分解反应和聚合反应, 使其组成分布趋于复杂; 衰变过程以分子链断裂的分解反应为主, 导致其黏度降低; 润滑油发生氧化反应和硝化反应, 添加剂被消耗, 生成酮类、多环芳烃、胺类、酸类化合物, 使润滑油颜色变深、酸值增加; 润滑油的分子质量分布发生变化, 说明润滑油衰变过程既发生分解反应也发生聚合反应, 但以链断裂的分解反应为主。     

航空润滑油氧化衰变影响因素及检测方法综述

航空润滑油在高速、高温且有金属催化的工作条件下极易被氧化,氧化导致的油品理化性能变化将直接影响润滑系统的正常工作,甚至危及飞机的安全飞行,因此加强对滑油的氧化衰变情况检测非常重要。论文简要分析了滑油氧化衰变的机理、危害及影响因素,对常用的检测方法进行了综述,并分析比较了检测方法的优缺点。     

复合抗氧剂对润滑油氧化的影响

模拟城市十五工况探究复合抗氧剂对润滑油氧化衰变的影响,选用噻二唑衍生物和对,对-二异辛基二苯胺,研究了其对润滑油的抗氧化作用及对进气阀和燃烧室沉积物的影响。噻二唑衍生物含量为0.05%,对,对-二异辛基二苯胺含量为0.5%,氨基甲酸钼含量为0.05%可以确定为复合抗氧剂最佳配比之一,通过台架试验与双怠速试验对比加入复合抗氧剂前后对碳排放的影响。结果表明,复合抗氧剂能有效抑制润滑油的氧化衰变,添加复合抗氧化剂可减少进气阀和燃烧室内的沉积物,减少汽车的碳排放。     

润滑油热氧化安定性试验方法标准比较分析

概述了物质组成、温度、金属和氧气等因素对润滑油高温氧化安定性的影响,将国内润滑油热氧化安定性试验方法标准分为旋转氧弹法、氧化管法、设备模拟法和仪器分析法,并进行分类介绍。     

我国润滑油氧化安定性试验方法标准及研究进展

将国内23项润滑油氧化安定性试验方法标准分为旋转氧弹法、氧化管法、设备模拟法和仪器分析法进行了归纳总结;概述了热失重分析仪、差示扫描量热仪、高效液相色谱测定仪和傅立叶变换红外光谱测定仪等现代分析仪器在润滑油安定性试验中的应用和研究进展情况。     

机组运行中润滑油的多参数测定及特征分析

为研究机组运行中润滑油的性能衰变规律,采用有机元素分析、红外光谱分析、热重分析技术建立了机组运行中润滑油多参数测定方法。获得了润滑油碳氢比、碳硫比、红外光谱特征波长强度比、失重起始温度、失重终止温度、最大失重速率等特征参数。碳氢比显示润滑油基本由CH_2组成;红外光谱分析结果表明,润滑油是以长链烷烃为主,其与黏度数据比对分析发现,波数为2 952.67 cm~(-1)时,红外吸收峰高相对质量分数与黏度呈负相关关系;TG-DTG曲线获得9个特征参数中,Ti和Te是润滑油稳定性的重要参数,润滑油在运行中不仅裂解生成小分子低沸点物质,同时也会聚合生成了一些难以氧化分解的高聚物、胶质等,且W_e与W_f呈良好负相关关系,而Wf与β'呈良好正相关关系。     

聚α-烯烃航空润滑基础油高温裂解衰变研究

随着飞机发动机工作温度的不断提高,在用航空润滑油品质衰变问题越发严重,特别是聚α-烯烃航空润滑基础油在高温作用下会发生严重的裂解衰变,由此引发聚α-烯烃航空润滑油性能改变,难以满足现代飞机发动机使用的要求。从聚α-烯烃的本体结构特点出发,分析了聚α-烯烃润滑基础油在高温作用下热裂解的衰变过程,比较了聚α-烯烃润滑基础油高温裂解前后理化性能的变化,并且论述了聚α-烯烃航空润滑基础油高温热裂解衰变程度评定方法。     

油品颜色变化研究进展

油品的颜色是衡量油品使用性能的一个最直接的外观质量指标。造成油品颜色发生变化的因素十分复杂,本文综述了燃料油、液压油和润滑油的颜色变化研究现状,对研究油品颜色衰变过程和衰变机理以及准确地掌握在用油品的换油周期具有重要意义。     

两种航空润滑油热氧化性能对比研究

利用高温模拟氧化装置,考察了某型国产航空润滑油和进口航空润滑油在不同温度下氧化后运动黏度、酸值、抗氧剂质量分数和抗磨性能与氧化时间的变化规律。结果表明:在175℃氧化时,两种航空润滑油的黏度、酸值、磨斑直径和抗氧剂质量分数随氧化时间的变化都比较小,可以长期使用;在200℃氧化温度以上,两种航空润滑油的各项指标随温度变化幅度较大,可以短期使用;短时间的氧化作用有利于提高航空润滑油的抗磨性能,磨斑直径有明显减小趋势;在所有氧化温度条件下,国产航空润滑油的各项性能指标均优于进口航空润滑油。     

金属磨粒对航空发动机润滑油氧化安定性的影响探究

从航空润滑油氧化安定性的定义、影响因素、危害等方面入手,对金属磨粒在航空润滑油氧化安定性方面的研究进行了综述,最后对航空润滑油氧化机理和金属作用机理进行了深入探讨。     

润滑油的指标检验要点解析

润滑油使用一段时间后会发生性能的降低或改变,必须适时更换,做到既不浪费,也保证设备的正常运行。就润滑油检验中的八大指标:水分、粘度、倾点、闪点、粘度指数、泡沫性、酸碱值、机械杂质进行详细论述,最后再简单阐述润滑油检验中的两点特殊指标:氧化安定性和热安定性。     

Functionalized polyethylene on property enhancement of lubricating oil and their performance evaluation study

Methyl methacrylate (MMA) functionalized polyethylene additives for improving the properties of lubricating oil has been investigated in which poly(MMA-co-ethylene) were synthesized by using three different polymerization techniques such as miniemulsion, post polymerization and reverse atom transfer radical polymerization with 1.0 molL −1 of MMA and 20 bar of ethylene pressure. The copolymers are block in nature with the composition of 1:3 molar ratios of ethylene:MMA which is independent of polymerization techniques used. ¹H NMR analysis confirmed the successful incorporation of the copolymers in the lubricating oil. Thermogravimetric analysis reveals that the addition of poly(MMA-co-ethylene) increases thermal stability of the additive doped lubricating oil by approximately 40°C with a single stage decomposition pattern. Flash point measurements show an increasing flash point values for copolymer doped lubricating oil. From rheological study, the viscosity index of base lubricating oil has found significant increases from 102 to 129 with the addition of poly(MMA-co-ethylene) and the higher molecular weight (MW) of this copolymer provides better thickening efficiency. However, copolymer with higher MW seems to be more susceptible to mechanical degradation resulting in lower shear stability whereas copolymer with lower MW acts as a better pour point depressant.     

Studies on reclaiming spent lubricating oils

Treatment of a spent lubricating oil by chromatography over activated charcoal, followed by extraction with furfural, improved its characteristics and led to a product which could be used as a blending stock for lubricating oils. l.r. and p.m.r. spectroscopy showed that degradation of the oil during service probably involved the additives and also produced changes in the hydrocarbon skeleton.     

Formulation and processing of virgin and recycled polyolefin/oil blends for the development of lubricating greases

This work has been focused on the development of polyolefins/oil blends potentially suitable as lubricating greases by studying the effect that some thermo-mechanical processing variables exert on their rheological properties and microstructure. Polyolefin/oil blends have been prepared by dispersing recycled and virgin polyolefins such as high-density polyethylenes (HDPEs) and polypropylenes (PPs) in mineral lubricating oil. Linear viscoelasticity functions have been significantly influenced by processing conditions. The nature of polymers used, specially the content of HDPE, has been found to modify the microstructure of blends yielding lower mechanical stability but, on the other hand, higher values of linear viscoelastic functions.     

Frictional dependence of graphene and carbon nanotube in diamond-like carbon/ionic liquids hybrid films in vacuum

The use of graphene and multi-walled carbon nanotubes (MWCNTs) additives as lubricants has received considerable interest because of their excellent mechanical and frictional properties. Given their structural differences, both carbon nano-additives are expected to have different synergistic effects at various conditions (from boundary to mixed lubrication). For applications in space, the tribological properties of graphene and MWCNTs additives in diamond-like carbon/ionic liquids hybrid films in different lubricating states at high vacuum were compared. The wear surfaces, transfer films, wear debris, and microstructures of the hybrid films were analyzed via Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results showed that MWCNTs and graphene present the different nano-scale tribological mechanisms and produce different lubricating effect on the hybrid films at different lubricating states.     

终缩聚熔体齿轮泵稳定运行探索

通过对聚酯装置增容和后接直纺长丝前后熔体齿轮泵工况变化的统计分析,研究其运行不稳定的原因,提出改造措施,包括滑动轴承润滑油槽,齿轮泵的机械密封,降低齿轮泵出口压力,改自动提速为手动提速等等。     

高分散稳定纳米金刚石润滑油的制备及其摩擦学性能

为了改善纳米金刚石颗粒(NDPs)在抗磨液压油(AHO)中的分散性,制备了酸氧化?高温热处理的NDPs (T-NDPs),将其与添加剂(油胺、聚异丁烯丁二酰亚胺T154和高碱值合成磺酸钙T106)混合后加入AHO中,制得含T-NDPs的AHO。用FESEM及Zeta电位仪、FT-IR和静态沉降法对其分散性进行表征,用四球摩擦磨损试验机、3D激光扫描显微镜和SEM/EDS对含T-NDPs的AHO的摩擦学性能和磨痕区域进行了分析。结果表明,酸氧化?高温热处理后,NDPs的平均粒径从270.2 nm降至153.5 nm,吸附添加剂后的T-NDPs的平均粒径为101.5 nm,添加剂可提高T-NDPs的油溶性并抑制其团聚,因而含T-NDPs的AHO具有良好的分散稳定性;T-NDPs含量为0.04wt%时,AHO的摩擦系数和磨斑直径比不加T-NDPs时分别降低13.2%和17.8%;T-NDPs作为润滑添加剂的减摩抗磨功效归因于其在摩擦界面起到支撑和滚动轴承的作用及在摩擦副表面参与润滑膜形成。     

润滑油加氢工艺

随着对高规格润滑油需求量的不断增加,常规溶剂抽提工艺已无法满足APIⅡ类和APIⅢ类润滑油基础油的生产,而加氢工艺越来越广泛地用于生产高规格润滑油。为了提升中国的润滑油品质,提高产品的市场竞争力,炼化企业正加大对加氢工艺在高规格润滑油基础油生产上的推广和应用。简述了几种润滑油加氢工艺及其特点。     

分形理论在润滑油添加剂合成研究中的应用

本文基于分形理论,利用图形处理软件对釜式法和超重力法合成的环烷酸钙的TEM照片进行处理,使用网格法对其分形维数进行了计算,并根据计算结果对不同合成条件下生成的环烷酸钙颗粒的形貌特征以及合成工艺进行了分析对比。结果表明:将分形理论应用于添加剂的产品的形态分析及合成工艺中,分形维数不仅被证明可以作为表征颗粒形貌特征及评价添加剂清净性能的重要参数,同时也与添加剂产品的合成工艺密切相关,可以间接作为评价添加剂合成工艺优劣的重要指标,同时从反应动力学和反应器结构两方面出发分析了添加剂颗粒成核的分形特征以及运动变化规律,说明添加剂合成过程不仅与物料的微观混合情况有关,同时也与反应器的组成结构关系密切。     

Utilization of olive-residue oil in the formulation of lubricating calcium greases

Calcium greases were manufactured from olive-residue oil in a closed reactor by substituting olive-residue oil for animal tallow. The results of the performance tests applied to the obtained greases showed that their physicochemical and mechanical characteristics are comparable to those of calcium grease manufactured industrially by using animal tallow. The substitution of part of the animal tallow with olive-residue oil increased the thermal and mechanical stability of the grease. Olive-residue oil could constitute, alone or in combination with animal tallow, a raw material in the formulation of lubricating calcium grease.