新型有机铋化合物的极压抗磨性能

利用四球试验机评价合成的环烷酸铋的极压抗磨性能以及与硫化异丁烯(T321)、ZDDP、磷酸三甲酚酯(TCP)、氯化石蜡(T301)常用添加剂之间的极压和抗磨协同性能。结果表明,环烷酸铋具有优良的极压抗磨性能,同硫化异丁烯之间有突出的极压协同作用,与ZDDP和氯化石蜡之间也有良好的抗磨协同作用和极压协同作用,可显著提高润滑油的极压性能和改善抗磨性能;但与磷类添加剂(磷酸酯)的协同性较差。     

有机铋化合物的极压抗磨协同性能研究

利用四球试验机评价了二丁基二硫代氨基甲酸铋(B iDDC)与二丁基二硫代氨基甲酸酯(V7723)、硫化异丁烯(VSB)和非硫磷钼酸酯(MoNO)添加剂的极压和抗磨性能,以及它们之间的极压和抗磨协同作用。试验结果表明:B iDDC添加剂在基础油中具有突出的极压性能,并且与V7723和VSB都表现出了较好的极压协同效果,但是在抗磨性能上,没有产生协同作用。然而B iDDC和MoNO添加剂复合后,不仅表现出了很好的抗磨协同作用,而且没有降低油样的极压性能。     

硫化异丁烯与ZDDP复配对菜籽油摩擦学性能的影响

以菜籽油为基础油,选择硫化异丁烯(T321)为极压添加剂、ZDDP为抗氧抗腐剂,采用均匀试验方法设计试验方案,并测定在不同添加剂含量下的pB值(最大无卡咬负荷)和WSD值(磨斑直径),利用逐步回归法和扫描电子显微镜(SEM)分析了基础油和添加剂之间的配伍性及其对菜籽油摩擦学性能的影响。结果表明:当硫化异丁烯的含量低时会降低菜籽油的承载能力,当含量高时可提高菜籽油的承载能力,ZDDP无论在低含量还是高含量均可提高菜籽油的承载能力。ZDDP对菜籽油抗磨性能的作用大于硫化异丁烯。     

铋化合物极压抗磨性能及其硫-铋元素复合作用探讨

研究了环烷酸铋、石油磺酸铋、二烷基二硫代磷酸铋和硫代氨基甲酸铋4类含铋添加剂的极压抗磨性能,同时对铋金属元素与硫元素之间的极压抗磨复合效果进行了分析.结果表明,铋型添加剂具有良好的润滑性能,并与含硫添加剂之间具有良好的协同效应,添加剂化合物中同时存在硫、铋元素时也表现出了良好的复合效果.     

磷酸三甲酚酯和 ＺＤＤＰ 的极压抗磨协同效应

利用四球试验机考察磷酸三甲酚酯 (TCP)和二烷基二硫代磷酸锌（ZDDP）的极压抗磨性能以及TCP和ZDDP复配后极压抗磨的协同效果。试验结果表明,TCP的抗磨性能要优于ZDDP,但ZDDP的极压性能要好于TCP;在较低的负荷下,TCP与ZDDP复配后能产生一定的协同抗磨效应;ZDDP添加剂可有效地改善TCP的极压性能。     

硼酸酯与含硫、磷、氯添加剂的减摩抗磨复合作用

用混料试验设计方法 ,研究了硼酸酯、氯化石蜡和二烷基二硫代磷酸锌 (ZDDP)的相互作用机理。混料试验结果认为 ,在极压性能方面 ,润滑油中的氯化石蜡含量影响与硼酸酯的复配效果。当氯化石蜡含量较少时 ,硼酸酯在摩擦表面优先形成沉积膜而屏蔽了氯化石蜡的表面成膜 ,表现为“对抗效应” ;当氯化石蜡含量 >7.5 % ,硼酸酯的减摩作用缓和了氯化铁膜的磨损 ,从而有利于氯化石蜡极压能力的提高 ,表现为“协同效应”。在抗磨性能方面 ,ZDDP与硼酸酯互相竞争金属摩擦表面 ,因而ZDDP与硼酸酯的复配可改善含硼油的抗磨性 ,但削弱了硼酸酯的减摩作用。在减摩性能方面 ,硼酸酯与氯化石蜡复合 ,表现为“对抗效应” ,但在一定配比下的三元添加剂复合(硼酸酯 0 .3%～ 2 .8% ,氯化石蜡 0 .8%～ 7.5 %和ZDDP 2 .1%～ 4.8% ) ,则有良好的“协同效应     

含硫极压抗磨添加剂在菜籽油中的摩擦学性能研究

利用四球磨损试验机考察了以硫化异丁烯和硫化棉籽油作为菜籽油极压抗磨添加剂时的摩擦学性能,通过测定2种添加剂在不同含量下的最大无卡咬负荷(pB)和不同条件下的磨斑直径(WSD),分析和研究了载荷、摩擦时间、添加剂含量对菜籽油摩擦学性能的影响。试验结果表明:硫化异丁烯可以明显提高菜籽油的承载能力和抗磨性能,硫化棉籽油对提高菜籽油的承载能力和抗磨性能效果不明显,硫化异丁烯在菜籽油中的承载能力和抗磨性能明显优于硫化棉籽油。试验还表明添加剂的含量并非越高越好,否则WSD值将增大。     

极压抗磨剂对复合锂钙基润滑脂性能及结构的影响

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。     

新型高效磷系极压剂的研究

根据分子设计原理,合成了一种磷系极压抗磨剂,试验结果表明,含磷添加剂具有优异的摩擦磨损性能,其PB、PD值有较大提高,已超过硫化异丁烯的极压抗磨性能.     

切削油中硝基化合物取代氯化石蜡的性能研究

采用四球极压和四球抗磨试验机以及攻丝扭矩试验机(MicroTap)考察硝基化合物和高分子聚合酯在纯油型金属切削液中的润滑极压性能,探讨使用硝基化合物取代氯化石蜡研发重负荷无氯切削油的可行性和机制。结果表明:硝基化合物润滑添加剂能有效提高切削油的润滑和抗磨性能;与硫类极压剂复配能显著提高切削油的烧结负荷,其润滑极压性能与氯化石蜡相当。     

Tribological properties of the film formed by borated dioctyl dithiocarbamate as an additive in liquid paraffin

This paper discusses the preparation of borated dioctyl dithiocarbamate as an oil-soluble antiwear and extreme pressure additive for lubricants. Its tribological performance when added to liquid paraffin was evaluated on a four-ball tester and a ring-on-block machine. The relationships between its performances and the concentrations are also given, and are compared with these of zinc dialkyldithiophospate (ZDDP). The results show that the novel compound possesses an excellent load-carrying capacity and friction reduction property similar to ZDDP, and exhibits better antiwear property than ZDDP above 392 N. In addition, the novel compound has good anticorrosive property and high thermal stability. The rubbed surface was investigated using X-ray photoelectron spectroscopy, and the antiwear mechanism was discussed.     

极压抗磨剂在GTL基础油中的感受性研究*

为探讨GTL基础油与常用极压抗磨剂感受性,分别将二烷基二硫代磷酸锌（T203）、磷酸三甲酚酯（T306）、二烷基二硫代氨基甲酸钼（S-525）、钼胺络合物（MOLYVAN 855）、硫磷酸复酯胺盐（T307）、硫化异丁烯（T321）和合成酯（VANLUBE 7723）与GTL基础油进行调配,利用四球摩擦试验机分别考察单剂和复配后油样的最大无卡咬负荷、磨斑直径和摩擦因数。结果表明：T307、MOLYVAN 855在GTL基础油中极压性和抗磨性最优;T203和VANLUBE 7723复配、T203和MOLYVAN 855复配对GTL基础油极压性和抗磨性能提升明显,而T203和S-525复配具有最佳的减摩效果;T306分别和S-525、T307和T321复配时表现出的极压性能变化趋势相似,而T306和T307复配在表现出良好极压性能的同时,兼具有较好的减摩抗磨效果。     

Limitations on use of ZDDP as an antiwear additive in boundary lubrication

Wear tests on rubbing elements under various contact pressures, oil temperatures and surface roughness were performed to elucidate the limitation conditions on antiwear performance of a typical zinc dialkyl dithiophosphate (ZDDP) added to a paraffin base oil. The analysis results indicate that the antiwear performance of ZDDP depends on the rates of recovery and growth of effective surface films. If these rates exceed that of scraping the films off the rubbing surfaces, antiwear performance is evident. However, the rates of recovery and growth of surface films are influenced by some essential factors, including the oil temperature, contact pressure and the surface roughness and hardness of rubbing elements. Under some suitable conditions, ZDDPs show favorable antiwear performance, but under some severe conditions, such as high pressure (over 90 MPa), high temperature (over 200 °C) with an insufficient concentration of ZDDP and the rubbing of a rough and harder surface on a softer surface, the antiwear performance of ZDDPs is negligible.     

Tribological behaviors and mechanism of sulfur- and phosphorus-free organic molybdate ester with zinc dialkyldithiophosphate

An oil-soluble sulfur- and phosphorus-free organic molybdate ester (ME) was synthesized. The antiwear and friction-reducing properties of ME with zinc dialkyldithiophosphate (ZDDP) in base oils were evaluated by four-ball tester. The results show that ME addition effectively reduced wear scar diameter (WSD) and friction coefficient (μ) as well as good antiwear synergism with ZDDP. The topography, composition and chemical states of typical elements on the worn scar were analyzed by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and X-ray photoelectron spectrometer (XPS). Smooth and light topography of worn scar further confirms the good antiwear synergism of ME with ZDDP. EDX and XPS analyses indicate that tribo-chemically boundary films formed on the rubbing surface consist of metal oxides, sulfides and phosphates, leading to enhancement of the antiwear and friction-reducing properties of the lubricants, and that the considerable MoS₂ layer especially plays an important role in improving antiwear and friction-reducing properties of oils. The proposed antiwear mechanism involves a synergy between ME and ZDDP.     

Tribological properties of P‐ and N‐containing organic compounds as potential extreme‐pressure and antiwear additives

An amine salt of an alkoxylphosphate (a P‐ and N‐containing organic compound, PN) was synthesised. Its extreme‐pressure, antiwear, and friction‐reducing properties were evaluated as an additive in liquid paraffin and a mineral oil. Tests were performed on a four‐ball friction and wear tester with an AISI 52100 steel ball self‐mated pair and the results were compared with those of sulphurised olefin (SO), zinc di‐n‐butyldithio‐phosphate (ZDDP), and dibutylphosphite (DBP). The morphologies of the worn steel surfaces were observed using a scanning electron microscope, while the binding energies of some typical elements on the worn surfaces were determined using X‐ray photoelectron spectroscopy. The additives were found to increase the load‐carrying capacity and to reduce wear and friction coefficient considerably. PN as an additive exhibits better load‐carrying, antiwear, and friction‐reducing properties than SO, ZDDP, and DBP under the same test conditions.     

Antiwear Behavior of ZDDP and Fluorinated ZDDP in the Presence of Alkylated Diphenyl Amine Antioxidants

Environmental regulations have called for a reduction of phosphorus content in engine oils in recent years. The anti-wear additive zinc dialkyl dithiophosphate (ZDDP), which is also an antioxidant, is one of the most important components of engine oil additives. ZDDP is a major source of phosphorus. One way to reduce phosphorus levels is to replace ZDDP with new environmentally friendly antiwear agents that have similar or superior wear performance compared to ZDDP. Another way to address the environmental issue is to reduce the amount of ZDDP in engine oils. At the same time, it is necessary to increase the efficiency of ZDDP by finding optimum conditions that would result in improved antiwear performance. The antiwear mechanism of ZDDP involves its degradation thermally and tribologically, leading to the formation of an antiwear film that consists of polyphosphates and sulphides. The structure of the antiwear film is almost similar in both types of degradation. But the breakdown efficiency of ZDDP is diminished by the parallel reaction of ZDDP with other additives, as well as the antagonistic effects of these additives. The new fluorinated ZDDP complex developed has shown better wear performance compared to ZDDP. This would allow the possibility of further reduction of phosphorus in engine oils compared to current levels. In this paper we study the interaction of ZDDP and fluorinated ZDDP with alkylated diphenylamine. The impact of antioxidant on wear performance was examined using a ball-on-cylinder tribometer. The interactions between ZDDP and the fluorinated ZDDP with the antioxidant were studied using NMR and the surface of the tribofilm was examined using SEM, TEM, and Auger spectroscopy.     

Research on Mutual Synergy of Antiwear Additives in Lithium Complex Grease

In recent years, with the enhancement of environment awareness, there has been a progressive reduction in permitted phosphorus and sulfur levels in lubricants. Sulfur and phosphorus are the most important elements of antiwear additives. Because of the reaction between additives, less mass of additives may have the same wear reducing properties when used together. However, there is uncertainty regarding the optimum amount and ratio of these additives. In this article, the influence of five kinds of antiwear additives—sulfurized olefin cottonseed oil (T405), sulfurized isobutylene (SIB), tricresyl phosphate (TCP), molybdenum dialkyl dithiophosphates (MoDTC), zinc dialkyl dithiophosphate (ZDDP), and their combination—on lithium complex grease have been studied by single-factor and orthogonal experiments. The single-factor tests show that T405 and SIB work well under low temperature, whereas TCP and MoDTC work well under higher temperature; ZDDP are multifunctional additives. It was proved that base grease has better antiwear properties at 150 than at 75°C. Additionally, sulfurized additives T405 and ZDDP and phosphate agent TCP could react better with lithium complex grease than the additives that have the same functional group. Furthermore, the results of orthogonal experiments show that the abrasion resistance of lithium complex grease is optimally best when T405, TCP, and ZDDP are blended with a ratio of 2:2:1. In addition, a synergistic effect between T405 and TCP is observed at ratios between 1:1 and 2:1. The morphology and element composition of the worn surfaces are examined by scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). Based on the two kinds of technology, the friction and wear mechanism of additives also have been studied.     

Copolymeric succinamic acids as antiwear additives: Synergistic and adverse effects

Copolymeric succinamic acid (COSMA) additives have been synthesised in the laboratory and evaluated for their antiwear performance, both alone and in combination with zinc dialkyl‐dithiophosphate (ZDDP) in HVI light neutral oil. COSMA additives show antiwear behaviour and, in combination with ZDDP, exhibit a good synergistic effect, reducing the wear‐scar diameter by 60% and increasing the initial seizure load from 50 kg to 85–95 kg.     

In situ observation of phosphorous and non-phosphorous antiwear films using a mini traction machine with spacer layer image mapping

Since 1940s the principal source of an antiwear additive in crankcase applications has been due to a family of additives known as zinc dialkydithiophosphate (ZDDP). In this study, we have applied a novel technique, the mini traction machine with spacer layer image mapping (MTM SLIM), to study film formation characteristics of monoblend oils containing only basestock and ZDDP and also fully forrmulated oils containing a boron antiwear additive. The purpose of this study was initially to understand the build up of ZDDP film and then to establish whether boron compounds alone could provide significant antiwear films under mixed rolling and sliding contact.