一种高水解稳定性有机B-N剂的摩擦学特性及机制研究

为改善有机B-N添加剂的水解稳定性,在分子结构中引入含氮官能团,设计合成一种新型含氮杂环类有机B N添加剂,利用四球式摩擦磨损试验机考察其在菜籽油中的摩擦学性能,并利用X射线吸收近边结构光谱（XANES）分析摩擦表面B元素的化学形态。研究表明：所合成的有机B N添加剂不仅具有高水解稳定性,而且在菜籽油中具有较好的抗磨性能;有机B-N添加剂在摩擦过程中发生摩擦化学反应,生成了主要由B2O3组成的边界润滑膜,从而提高菜籽油的抗磨性能。     

一种新型的含稀土和锡的复合润滑添加剂的摩擦学特性研究

合成了含稀土和锡的复合润滑添加剂RES2 ,其在室温和 - 10℃的条件下均具有良好的油溶性 ,不含硫、磷元素 ,具备绿色添加剂的特征。它具有比ZDDP更好的抗磨减摩性能 ,有望作为新型的高效多功能润滑添加剂在工业实际中得到应用。钢球的表面分析表明 ,复合添加剂在摩擦表面形成的含稀土元素和锡元素的化学反应膜可能是其具有良好摩擦学性能的主要原因     

磷、氮改性油酸水溶性润滑添加剂的合成及摩擦学性能

以油酸为原料,合成了一种新型含磷、氮水溶性润滑添加剂,用红外光谱仪对其主要官能团进行了鉴定,用摩擦磨损试验机考察了合成产物在水中的摩擦学性能,用扫描电子显微镜观察分析了磨斑表面的形貌,并用X射线光电子能谱仪分析了钢球磨损表面典型元素的化学状态。结果表明：含磷、氮水溶性润滑添加剂具有优良的抗磨和减摩性能,添加剂在钢球磨损表面形成了吸附膜和（或）摩擦化学反应膜,表现出良好的抗磨和极压作用,从而提高了添加剂在中水的摩擦学性能。     

纳米陶瓷润滑油添加剂润滑机制研究

研究了纳米陶瓷润滑油添加剂的润滑机制.采用四球试验机考察了纳米陶瓷润滑油的抗磨性能和极压性能,利用NT场致发射扫描式电子显微镜、高分辨率扫描电子显微镜、X射线光电子能谱仪,观察了磨损表面的纳米粒子形貌,分析了磨损表面的形貌及表面元素成分.结果表明,纳米陶瓷润滑油润滑时,摩擦表面的磨斑很光滑,磨斑表面有Si3N4存在;纳米陶瓷添加剂具有很好的抗磨和极压性能;纳米陶瓷粒子具有"滚珠效应".     

氧化镁/氧化锌导电硅脂的性能研究

氧化镁可以提高摩擦表面摩擦膜的致密性,氧化锌也具有优良的抗氧化、抗磨减摩性能。以不同含量的氧化镁和氧化锌为添加剂,二甲基硅油为基础油,聚四氟乙烯作稠化剂,制备导电润滑硅脂,并分别对硅脂的滴点、体积电阻率和摩擦学性能进行测试。结果表明:氧化镁和氧化锌添加剂都可以提高硅脂的滴点、导电性,其中氧化锌作为添加剂的硅脂的滴点高于氧化镁,体积电阻率小于氧化镁;氧化锌和氧化镁添加剂加入能够降低硅脂摩擦因数、减小磨损,且氧化镁作为添加剂表现出更优秀的抗磨减摩性能。XPS分析表明,氧化镁和氧化锌添加剂在摩擦过程中在摩擦表面发生化学反应形成了含Fe、Zn和Mg元素的反应膜,能够填充磨痕表面,起到了减摩抗磨的作用。     

纳米金刚石油精添加剂摩擦学性能评价

对含纳米金刚石颗粒的机油添加剂进行了摩擦磨损性能的试验研究。结果表明,含纳米金刚石颗粒添加剂的润滑油与基础油相比,具有良好的摩擦学性能。在基础油中,加入纳米金刚石机油油精,可以提高润滑剂的抗磨性能、减摩性能、承载能力。通过添加剂的物理性质分析、摩擦学性能分析及润滑剂的理化性能分析等,验证了含纳米金刚石颗粒添加剂摩擦磨损性能的影响机理,即表面的吸附、滚珠和自润滑的特性。     

新型含氮磷酸酯添加剂的合成及摩擦学性能研究

以脂肪酸甲酯为原料合成一种新型含氮磷酸酯添加剂,通过红外对其结构进行表征,采用四球摩擦试验机考察其在不同基础油中的摩擦学性能,并用扫描电子显微镜和能谱仪观察分析磨痕表面的形貌及元素分布。结果表明:含氮磷酸酯添加剂具有良好的热分解性能和极压抗磨性能;实验后在钢球表面发现了磷元素,表明在摩擦过程中,含氮磷酸酯添加剂通过化学反应在摩擦表面生成了磷酸铁等化合物,从而起到了极压抗磨的作用。     

一种不含硫磷氮硼酸酯的摩擦学性能研究

合成了一种不含硫磷氮的新型硼酸酯,在四球摩擦磨损试验机上研究了它们作为润滑油添加剂的摩擦学性能,用X-射线光电子能谱(XPS)分析了钢球磨损表面典型元素的化学状态,用加压差热扫描示量法(PDSC)评价了其在基础油中的抗氧化性能。实验结果表明,合成的硼酸酯具有良好的抗磨性能,是一类新型无硫磷氮环保型润滑油添加剂;在摩擦过程中,硼酸酯添加剂在钢球表面形成了一层含硼膜,这层膜具有良好的摩擦性性能;硼酸酯添加剂具有良好的氧化安定性,加入添加剂后基础油的起始氧化温度增加18.54℃。     

纳米CaCO3、Cu混合物润滑油添加剂的摩擦学性能

采用纳米碳酸钙、纳米铜粒子混合物作为润滑油添加剂,利用四球摩擦磨损试验机考察了含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能;用扫描电子显微镜（SEM）考察了磨痕表面的形貌;用原子力显微镜和扫描电子显微镜（SEM）观察分析了在磨损表面纳米粒子的形态与分布。研究结果表明,纳米碳酸钙、纳米铜的混合粒子的总添加量为0.6％,质量比为1：1时,润滑油具有最佳的摩擦学性能;润滑油中纳米碳酸钙、纳米铜混合物粒子添加剂的优良摩擦学性能与纳米粒子在表面存在形态相关。     

含纳米微粒的多功能复合润滑油添加剂

研究了用爆炸法制备纳米微粒经表面改性与功能添加剂复配的摩擦学性能。结果表明,含表面改性的纳米微粒的复合润滑油添加剂有优异的极压抗磨减摩性能,能显著地降低接触部件的磨损,延长机械部件的使用寿命,并对已磨损表面具有一定的自修复作用。     

肼基硼酸酯的水解稳定性及摩擦学性能研究

以水合肼为原料合成硼酸三乙醇肼酯（肼基硼酸酯）;用高斯计算硼酸三乙酯、硼酸三乙醇胺酯、硼酸三乙醇肼酯3种硼酸酯水解前后各化合物中硼原子所带的电荷量;采用敞口法分别测定3种硼酸酯的水解稳定性;利用四球摩擦磨损试验机考察合成的肼基硼酸酯在菜籽油中的摩擦学性能。结果表明：合成的硼酸三乙肼酯具有良好的水解稳定性,是硼酸三乙酯的2 800倍,硼酸三乙醇胺酯的2.3倍,并且在低载荷下硼酸三乙肼酯有较好的极压减摩和抗磨性能。利用XPS、SEM考察磨损钢球表面的成分和形成的边界膜结构,结果显示所加入的添加剂都吸附在钢球表面,形成了以B2O3为主的沉积膜和以氮元素为主的吸附膜等组成的润滑膜,阻止了摩擦磨损的进一步进行。     

Tribological study and mechanism of B–N and B–S–N triazine borate esters as lubricant additives in mineral oil

The tribological study of N-containing heterocyclic borate esters as lubricating additives had been the research hotspot. In this work, B–N and B–S–N triazine borate esters were synthesized and their antiwear/extreme pressure (AW/EP) properties were studied. Results showed the synthetical additives had good AW performance. However, B–S–N triazine borate ester showed excellent EP property while B–N triazine borate ester hardly owned EP property. The hydrolytic stability of borate ester additives was improved by the formation of coordination of nitrogen to boron. The XANES spectroscopy analysis showed that there was a layer of borate–oxygen–iron inorganics in the tribofilms. The existence of iron sulfate and iron sulfide guaranteed good AW/EP properties of B–S–N triazine borate ester additive in mineral oil.     

The hydrolytic stability of borates used as oil additives

Eleven borate ester compounds were synthesised and their hy-drolytic stabilities were compared. The results indicated that the hydrolysis problem of borate esters can be solved by introducing N, N-dialkylamino-ethanol with alkyl groups containing more than or equal to 4 carbon atoms in the esters. It was believed that the formation of a stable five-member ring structure in molecules involving coordination of the nitrogen atom with boron contributes substantially to the resistance to hydrolysis of such compounds.     

Borate esters used as lubricant additives

Borate esters possess friction‐reducing, antiwear, and anti‐oxidant characteristics when blended in lubricating oils. However, borate esters are susceptible to hydrolysis. The formation of a stable five‐member ring structure in the ester molecules, involving coordination of nitrogen with boron, contributes substantially to the resistance to hydrolysis of borate esters. The susceptibility of borates to hydrolysis can be reduced by introducing N,N‐dialkylaminoethyl groups with alkyl radicals containing more than three carbon atoms. X‐ray photo‐electron spectroscopy and X‐ray diffraction reveal that the borate ester can be adsorbed on the rubbing surface, and some of the adsorbed borate film degrades and forms boron nitride. Four‐ball wear tests indicate that the combination of oil‐soluble copper, tin, and cadmium compounds with organoborates gives better antiwear properties than the components separately. An antiwear synergistic mechanism is postulated in which borates with electron‐deficient boron p orbitals catalyse the tribo‐reduction of the metal compounds on the rubbing surfaces, producing elemental metals.     

Friction and wear behavior of diamond-like carbon coating on plasma nitrided mild steel under boundary lubrication

The friction and wear properties of synthetic ionic liquid functionalized borate esters as additives in poly-alpha-olefin (PAO) were measured for diamond-like carbon (DLC) coating on plasma nitrided AISI 1045 steel. Results show that the borate esters gave much better friction–reduction and antiwear properties for DLC coating/steel and DLC coating/DLC coating sliding pairs than zinc dialkyldithiophosphate (ZDDP). In addition the DLC coating had much better wear resistance than the nitrided mild steel substrate, indicating that duplicate surface modification was more effective in significantly increasing the wear resistance of mild steel.     

The tribological behaviour and mechanism of action of sulphur-containing borate esters in rape seed oil

Three sulphur-containing borate esters and one borate ester based on boric acid and n-octanol were synthesised. The antiwear and friction-reducing properties of these synthetic compounds as additives in rape seed oil were examined using a four-ball machine. The relationship between the additive structure and tribological properties was explored, and the lubrication mechanisms of the additives investigated. The worn surfaces of a steel ball lubricated with the additive-containing rape seed oil were analysed using X-ray photoelectron spectroscopy and scanning electron microscopy. The elemental compositions of, and distributions in, the worn steel surfaces were determined with an electron probe micro-analyser. It was found that sulphur-containing borate esters as additives in rape seed oil at appropriate concentrations can be effective in improving antiwear and friction-reducing behaviour. The rape seed oil base stock experiences competitive adsorption and tribochemical reactions with additives on the rubbing steel surface. The introduction of the active element sulphur into the borate ester additives functions to improve the tribological behaviour of the base stock by increasing the rate of formation of a protective layer on the rubbing steel surface. However, the tribological behaviour of the additives is not dependent on the number of sulphur atoms in the additive molecules, and further work is needed to investigate the possible dependence of this behaviour on the ratio of boron to sulphur in the additive molecules.     

Tribological Behaviors of Different Diamond-Like Carbon Coatings on Nitrided Mild Steel Lubricated With Benzotriazole-Containing Borate Esters

Three synthesized benzotriazole-containing borate esters were separately added into poly-alpha-olefin (PAO) as additives, using molybdenum dithiocarbamate (MoDTC) as the comparison. The friction and wear behavior of Ti-DLC and Ti/Al-DLC coating on nitrided AISI-1045 steel sliding against AISI 52100 steel under the lubrication of PAO containing various additives was evaluated using a reciprocating ball-on-disk friction and wear tester. The morphology and chemical feature of the worn surfaces of the DLC coatings were observed and analyzed using a three dimensional (3D) surface profiler, a scanning electron microscope (SEM), and an X-ray photoelectron spectroscope (XPS). Results show that the three kinds of benzotriazole-containing borate esters as additives in PAO had much better tribological properties than MoDTC; the wear resistance of Ti/Al-DLC coating was better than Ti-DLC coating.     

Tribological studies on a novel borate ester containing benzothiazol-2-yl and disulfide groups as multifunctional additive

A novel borate ester derivative containing benzothiazol-2-yl and disulfide group (BTSB) was synthesized and characterized. Its tribological properties used as EP and multifunctional additive in rapeseed oil were evaluated using a four-ball tribometer, and its action mechanisms were investigated by the X-ray photoelectron spectroscopy. Results show that the BTSB possesses comprehensive tribological properties in load-carrying, friction-reducing, antiwear, corrosion-inhibiting, and anti-oxidation, which probably has a chance to replace ZDDP partially. Moreover, the decomposed borate esters, organic sulfide and nitrogen adsorbed on worn surface were detected, and S element in BTSB reacted with metal and generated FeSO₄, both of which contributed to the formation of boundary lubricating film.     

Preparation and tribological properties of the N‐containing heterocyclic borate esters and Cu microparticles as lubricant additives in base oil

In this paper, four kinds of N‐containing heterocyclic borate esters and polyvinyl pyrrolidone‐protected Cu microparticles were synthesised and characterised. Their tribological properties as lubricant additives in industrial white oil were evaluated using a four‐ball tribometer, and their lubrication mechanisms were investigated by X‐ray photoelectron spectroscopy. The results showed that the anti‐friction and anti‐wear performance of the base oil can be significantly improved by the addition of N‐containing borate esters and Cu microparticles, and they present synergistic tribological effect. Moreover, X‐ray photoelectron spectroscopy results showed a lubricating tribochemical reaction film containing B₂O₃, FeB, FeO, Fe₂O₃ and so on is formed on the worn surface. In addition, Cu microparticles as rolling bearings, which transform sliding friction to rolling sliding and the formation of the Cu microparticles deposited film, are probably responsible for the improvement of tribological performance. Copyright © 2017 John Wiley & Sons, Ltd.