油润滑条件下有机物修饰纳米铜颗粒改善铁基摩擦副摩擦磨损的研究

在球盘式摩擦磨损试验机上考察了有机物修饰的纳米铜颗粒作为50CC润滑油添加剂的摩擦学性能；采用SEM和EDS分析了磨损表面形貌和表面膜元素组成。探讨了纳米铜颗粒的摩擦学作用机制：结果表明：有机物修饰的纳米铜颗粒作为添加剂能显著改善50CC润滑油的抗磨减摩性能，含0．05％纳米铜油样润滑下的摩擦因数与磨损量同基础油润滑下相比分别降低了27．6％与60％。分析后认为，纳米铜颗粒通过对摩擦表面进行修复及在摩擦表面成膜两种作用有效地改善了摩擦磨损性能。     

坡缕石载铜复合纳米润滑添加剂的制备及摩擦学性能研究

使用化学还原法制备坡缕石载铜复合纳米颗粒,以铸铁HT200作为摩擦副,采用MMU-10G摩擦磨损试验机研究该纳米颗粒作为润滑添加剂的摩擦学行为,使用EPMA-1600电子探针、金相显微镜、Genesis能谱仪进行试样磨损面形貌观察和组成元素分析。实验结果表明:该纳米复合颗粒作为润滑添加剂具有优异的减摩效果和良好的抗磨性能,与基础油150N相比,平均摩擦因数下降66.2%,对应的摩擦副试件磨损失重减少80.9%,在试件表面生成由纳米坡缕石和纳米铜共同组成的自修复膜。     

表面修饰FeS纳米微粒的研究(Ⅱ)--摩擦学特性研究

用四球摩擦磨损试验机考察了二烷基二硫代磷酸（DDP）修饰FeS纳米微粒作为润滑油添加剂的摩擦学行为.结果表明,DDP修饰FeS纳米微粒在极低的添加量时即具有良好的抗磨效果,但不能降低基础油的摩擦因数;磨损表面分析表明钢球表面形成了边界润滑膜,使摩擦学性能得到明显改善.     

表面未修饰及修饰纳米SiO2对锂基脂摩擦学性能的影响

利用四球摩擦磨损试验机考察了表面未修饰及修饰纳米SiO2作为添加剂对锂基脂摩擦学性能的影响;采用扫描电子显微镜观察了钢球磨损表面形貌,并采用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,以探讨2种纳米SiO2添加剂的减摩抗磨作用机理。结果表明,采用化学法和物理法制备的表面修饰及未修饰纳米SiO2作为添加剂均能通过形成复合边界润滑膜而改善锂基脂的减摩抗磨性能,其中采用物理法制备的未修饰纳米SiO2的减摩作用略优,而采用化学法制备的表面修饰纳米SiO2在高载荷下的抗磨作用较优。     

纳米铜润滑添加剂在四球机上的摩擦学性能研究及机理探讨

用MRS-10J四球摩擦磨损试验机考察了N68基础油和添加了自修复纳米铜润滑添加剂NT1的N68NT1的摩擦学性能,用扫描电子显微镜（SEM）、x射线能量色谱仪（EDS）分析了钢球表面的磨斑形貌和组成,同时初步分析了纳米铜润滑添加剂的润滑机理.结果表明：自修复纳米铜润滑油添加剂NT1能显著改善N68基础油的摩擦学性能;在载荷为296 N、392 N、490 N,试验时间为30 min的试验条件下,摩擦副的摩擦因数同基础油的相比分别下降了33.8%、39.4%和55.5%;钢球的磨斑直径分别下降了46.5%、45.6%和32.5%;同N68相比,N68NT1的pB值提高了33.3%;这可能同摩擦过程中钢球表面上沉积膜的协同作用有关.     

纳米二氧化铈与蛇纹石混合物作为润滑油添加剂的摩擦学性能研究

采用表面活性剂将蛇纹石、纳米二氧化铈以及他们的混合物稳定分散于PAO4基础油中,利用摩擦磨损试验机分别考察蛇纹石、纳米二氧化铈以及蛇纹石与二氧化铈混合物作为润滑油添加剂的摩擦学性能,借助金相显微镜观察磨损表面形貌并测量磨斑直径,并采用能量色散谱仪(EDS)分析磨损表面的元素组成。结果表明:蛇纹石、纳米CeO_2和蛇纹石/CeO_2复合颗粒都可以显著改善润滑油的减摩抗磨性能,而添加蛇纹石/CeO_2复合添加剂的润滑油的摩擦学性能更佳,其中添加质量分数0.25%纳米二氧化铈与0.25%蛇纹石混合物的润滑油的摩擦学性能最佳。蛇纹石/CeO_2复合颗粒优异的摩擦学性能归因于其在磨损表面形成了吸附膜和Fe_2O_3、SiO_2化学反应膜,其中Ce元素可能起到了催化剂的作用。     

纳米碳酸钙、稀土复合粒子用作润滑油添加剂的研究

选择合适的表面活性剂制备含纳米碳酸钙和纳米稀土复合粒子添加剂的润滑油,采用四球摩擦磨损试验机考察了润滑油的摩擦学性能;用扫描电镜与X射线光电子能谱仪分析了磨损钢球表面的形貌、化学组成和状态。结果表明：纳米碳酸钙、纳米稀土复合粒子的最佳添加方式为：CaCO3与RE质量比为1：1,总质量分数为0．6％;此时润滑油具有最佳的抗磨、减摩性能,润滑油的抗磨、减摩机理与纳米粒子存在形态以及它们的协同作用有关。     

二维层状Ni/β-Ni(OH)2纳米复合材料的制备及其摩擦学性能研究

采用水热反应制备出β-Ni(OH)2,然后通过水热还原得到Ni/β-Ni(OH)2纳米复合粉体材料,采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对复合材料的相结构、成分及形貌进行表征分析。采用四球摩擦磨损试验机评价制备的Ni/β-Ni(OH)2作为润滑油添加剂的摩擦学性能,基础油为PAO6。摩擦试验后,采用SEM分析典型试验钢球磨斑的表面形貌,利用能谱仪(EDS)研究磨斑表面化学元素的组成,探讨Ni/β-Ni(OH)2纳米复合润滑添加剂的减摩抗磨机制。结果表明:Ni/β-Ni(OH)2纳米复合材料作为润滑添加剂具有极好的减摩抗磨性能,显著优于基础油PAO6和未负载纳米Ni的二维β-Ni(OH)2层状材料;与基础油相比,添加0.1%质量分数Ni/β-Ni(OH)2添加剂的油样的摩擦因数和磨斑直径分别降低了17.6%和41.5%;Ni/β-Ni(OH)2纳米复合粉体综合了纳米Ni及层状β-Ni(OH)2两部分结构特性,在摩擦过程中,复合材料中的纳米金属粒子Ni与层状结构材料β-Ni(OH)2能够相互增强起到协同润滑作用。     

油溶性CuO纳米颗粒的抗磨性能研究

利用四球摩擦磨损实验机考察了油酸铜修饰CuO纳米颗粒作为润滑油添加剂的抗磨性能,并用扫描电子显微镜（SEM）和X-射线光电子能谱（XPS）等对钢球磨损表面进行了分析。摩擦磨损试验结果表明,当添加质量分数仅为0.025%时,油酸铜修饰CuO纳米颗粒作为润滑油添加剂即能够明显提高基础油的抗磨能力。SEM及XPS分析结果表明,油酸铜修饰CuO纳米颗粒作为润滑油添加剂在摩擦过程中形成了一层富含Cu2O和Fe2O3的化学反应膜,正是这层膜的存在使得其表现出良好的抗磨性能。     

油酸修饰纳米粒子的摩擦学性能比较

利用化学法合成了表面为油酸所修饰的PbS、PbO和ZnS纳米粒子,由于无机纳米粒子表面有一层由油酸组成的长链有机化合物,使得所修饰的PbS、PbO和ZnS纳米粒子在基础油中有良好的分散性,能够作为润滑油添加剂。用四球摩擦磨损试验机分别考察了它们作为润滑油添加剂的摩擦学行为,结果表明,无机纳米核的化学组成、大小,以及摩擦过程中所形成边界润滑膜的成膜机制对油酸修饰纳米粒子作为润滑油添加剂的摩擦学性能影响不大,所合成的油酸修饰PbS、PbO和ZnS纳米粒子作为润滑油添加剂都能够明显提高基础油的减摩抗磨性能。     

噻唑衍生物在菜籽油中的摩擦学性能研究

合成了两种噻唑衍生物，采用热重分析对其热稳定性进行了评价；利用四球摩擦磨损试验机考察了其在菜籽油中的摩擦学性能，并用扫描电子显微镜和x射线光电子能谱仪观察分析了磨斑表面的形貌和元素化学状态。结果表明：噻唑氨基甲酸衍生物添加剂可显著改善菜籽油的减摩抗磨性能和承载能力；含上述添加剂的菜籽油在摩擦过程中发生了摩擦化学反应，生成了含菜籽油甘油酯、有机硫化物、硫酸亚铁等组成的边界润滑膜，从而改善了菜籽油的摩擦学性能。     

新型S-N型三取代三嗪衍生物的合成及其与磷酸三甲酚酯在菜子油中的摩擦学研究

合成了一种新型无磷三正辛硫基取代三嗪衍生物（TOTY），利用四球摩擦磨损试验机考察了单剂TOTT、磷酸三甲酚酯（TCP）以及含不同质量比的TOTY和TCP的复合添加剂在菜子油中的摩擦学研究；用x射线光电子能谱仪（XPS）和扫描电子显微镜（SEM）分析了磨损表面形貌和元素化学形态。结果表明：所考察的添加剂都能有效提高基础油的承载能力；在一定的条件下，单剂TOTY和TCP能够有效地提高基础油的减摩和抗磨性能；TOTY／TCP复合剂在基础油中表现出协同抗磨和减摩效应。在摩擦过程中，含上述添加剂的菜子油与摩擦副表面发生了复杂的摩擦化学反应，在摩擦副表面生成混合边界润滑膜，从而起到了减摩抗磨作用。     

A study of the tribological behaviour and action mechanism of thiophosphates in rape seed oil

Tri‐n‐butyl phosphate and two thiophosphates, tri‐n‐butyl thiophosphate and tri‐n‐octyl thiophosphate, were synthesised. The tribological properties of the compounds as additives in rape seed oil for a steel‐steel friction pair were investigated with two four‐ball machines. The worn surfaces of the steel balls lubricated with the additive‐containing rape seed oil were analysed by means of X‐ray photoelectron spectrometry and scanning electron microscopy. Typical elemental distributions in the worn steel surfaces were analysed with an electron probe micro‐analyser. It was found that rape seed oil containing thiophosphates as additives at appropriate concentrations demonstrated better tribological properties than tri‐n‐butyl phosphate. Tribochemical reactions were found to be involved for the steel‐steel friction pair lubricated with the rape seed oil containing the synthetic phosphates, with the formation of a boundary lubricating film composed of a glyceride of the rape seed oil and the tribochemical reaction products of the additives. This is assumed to contribute to the improvement of the tribological properties of the rape seed oil base stock. The action mechanism of the additives is also discussed.     

The tribological behavior of thiophosphates as additives in rapeseed oil

Two kinds of thiophosphate, tri-n-octyl thiophosphate and tri-n-octyl tetrathiophosphate, were synthesized. The tribological behavior of the synthetic compounds and tricresyl phosphate as additives in rapeseed oil for steel-steel frictional pair was investigated with a four-ball machine. The relationship between the additive structure and tribological properties was explored, while the lubrication mechanisms of the additives were investigated as well. Thus the worn surfaces of the steel ball lubricated with the additive-containing rapeseed oil were analyzed by means of X-ray photoelectron spectrometry and scanning electron microscopy, and the elemental compositions and distributions in the worn steel surfaces were observed and determined with an EPMA-810Q electron probe micro-analyzer. It has been found that the synthetic thiophosphates as additives in rapeseed oil at proper concentrations show better tribological properties than tricresyl phosphate. Tribochemical reactions were involved for steel–steel frictional pair lubricated with the rapeseed oil containing thiophosphates, with the formation of a boundary lubricating and protecting film composed of glyceride of rapeseed oil and tribochemical reaction products of the lubricants. This contributes to improve the tribological properties of the rapeseed oil base stock.     

Tribological studies of epoxy and its composite coatings on steel in dry and lubricated sliding

Industrial lubricants are invariably used with additives (with high sulfur and phosphorous contents) for tribological performance enhancement. However, these additives are environmentally very harmful. Hence, there is an urgent need to find alternate solutions for enhancing the tribological performance of lubricants and components without the use of harmful additives. The objective of this work is to investigate the feasibility of using polymer composite coatings in enhancing the tribological properties of steel surfaces in dry and base oil lubricated conditions. Pure epoxy and its composite (with 10?wt-% of graphene or graphite powder) films were coated onto steel substrates and tested under dry and base oil lubricated conditions. Friction and wear experiments were conducted on a ball on cylinder tribometer between polymer/composite coated cylindrical steel surface (shaft) and an uncoated steel ball as the counterface. Tests were conducted at various normal loads and speeds. In dry condition at 3 N load and 0.63?m s^??1 sliding speed, the wear life of epoxy was increased by five times and coefficient of friction was nearly the same (0.18) on inclusion of graphene nanoparticle. In lubricated case, epoxy/graphene composite coating performed eight times and more than five times better than pure epoxy and epoxy/graphite respectively.     

Tribological Properties of Muscovite/La2O3 Composite Powders as Lubricant Additives

Muscovite/La₂O₃ composite powders were prepared by ball-milling solid-state chemical reaction at room temperature. The phase composition and micromorphology of the composite powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The tribological properties of different samples were tested and compared using four-ball wear testing on an MMW-1A multifunctional friction and wear testing machine. The SEM micrography and energy spectrum of the composite powders illustrated that La₂O₃ particles were coated on the surface of muscovite particles. The results of the friction tests indicated that lubrication oil with muscovite/La₂O₃ composite powders presents better friction reducing and antiwear properties than that of the base oil, and the friction coefficients and diameters of wear scars decreased by 47.6 and 11.2% using 500SN base oil with 0.6g/L of muscovite/La₂O₃ composite powders as additives, respectively. The composite powders with 5 wt% La₂O₃ present the best comprehensive tribological properties. The micromorphology and chemical composition of the worn surface were analyzed by SEM and EDX, which confirm that the composite powders directly participate in the complicated physicochemical process of reactions on the worn surfaces, therefore improving the tribological properties of the base oil.     

一种硫磷氮衍生物在菜籽油中的摩擦学研究

通过Mann ich合成了2种有机环胺的硫磷酸酯衍生物,在四球摩擦磨损试验机上研究了它们作为菜籽油添加剂的摩擦学性能。实验结果表明,该类化合物具有良好的极压抗磨性能,能提高菜籽油的极压抗磨性能。通过用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,显示在摩擦过程中,钢球表面形成了一层含硫、磷无机膜和含氮的有机膜。     

双羟基硬脂酸在蓖麻油中的润滑性能的研究

利用四球摩擦磨损试验机考察了所合成的双羟基硬脂酸在蓖麻油中的摩擦学性能．并用扫描电子显微镜观察分析了磨斑表面的形貌。结果表明：双羟基硬脂酸添加剂可以显著改善蓖麻油的抗磨减摩性能和极压性能；含上述添加剂的蓖麻油在摩擦过程中发生了化学吸附反应，在摩擦表面形成了含双羟基硬脂酸的吸附膜．从而改善了蓖麻油的摩擦学性能。     

Tribological properties of crown‐type phosphate ionic liquids as lubricating additives in rapeseed oils

The friction and wear properties of rapeseed oils with different concentrations and crown‐type phosphate ionic liquids were studied by an Optimol SRV oscillating friction and wear tester. Crown‐type phosphate ionic liquids have better solubility than conventional ionic liquids in rapeseed oils. The tribological test results showed that the crown‐type phosphate ionic liquids as lubricating additives in rapeseed oil exhibited better tribological performance than the base oil for steel/steel friction pair under various loads. It is noted that the friction pair showed the least friction coefficient and wear volume when the concentration of ionic liquids was 1 wt.%. The better tribological properties of friction pair should be attributed to the effective boundary films formed in the worn surface, on various tribochemical products, organometallic products and iron oxides. Copyright © 2012 John Wiley & Sons, Ltd.