纳米添加剂润滑条件下GCr15/45#钢摩擦磨损性能影响

随着纳米科技的发展和对纳米材料功能特殊性的认识,纳米材料作为添加剂开始越来越多的应用到润滑和抗磨自修复研究中。利用PLINT NENE-7型磨损试验机,选用中石油兰州润滑油厂生产的中负荷工业闭式齿轮油L-CKC220作为润滑油,研究了纳米氮化钛,纳米氧化铝,纳米二氧化硅作为添加剂对GCr15/45#钢摩擦副摩擦磨损特性的影响。分析不同纳米材料对摩擦因数曲线、磨斑形貌(SEM)及EDX能谱分析图的影响。结果表明:3种纳米添加剂均能使摩擦副的摩擦因数明显降低。     

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。     

硅镁型复合纳米添加剂的摩擦学及自修复性能研究

用化学方法制得粒径约为40 nm的硅镁型复合纳米添加剂,分别采用四球摩擦磨损试验机、环-块摩擦磨损试验机和齿轮试验机考察了其作为矿物油添加剂的抗磨减摩性能及对磨损表面的修复作用.用扫描电子显微镜、粗糙度测定仪以及X射线光电子能谱仪等对摩擦副磨损表面进行了分析,并探讨其修复作用机制.结果表明:制备的硅镁型复合纳米添加剂具有优良自修复性能,可以很好覆盖磨损表面,能显著降低磨损表面的粗糙度.其自修复作用机制是由于硅镁型复合纳米粒子在摩擦表面形成沉积并在接触区的高温高压下熔融铺展形成低剪切强度的表面膜, 由于这层膜的剪切强度比较低,可以减少摩擦界面的粘着磨损,故表现出良好的减摩抗磨和自修复性能.     

SiO2/MgO复合纳米添加剂的摩擦学和磨损修复性能研究

用化学方法制得粒径约为40nm的SiO2／MgO复合纳米粒子。用四球机和环-块试验机分别考察了其在矿物油中的抗磨减摩和自修复性能；用SEM和XPS分析了磨斑表面的形貌和元素组成，并探讨其润滑和自修复作用机理。研究表明：SiO2／MgO复合纳米添加剂具有优良的减摩、抗磨和自修复性能；在接触区的高温高压下SiO2／MgO复合纳米粒子在摩擦表面熔融、铺展和沉积，形成低剪切强度的表面膜，既提高了抗磨减摩性能，又表现出良好的自修复效果。     

羟基硅酸盐/纳米铜复合添加剂摩擦学性能研究

由羟基硅酸镁和纳米铜粉体按质量比1∶1组成复合添加剂,利用MJ-800型四球摩擦磨损试验机考察复合粉体、硅酸盐粉体和纳米铜分别作为N68基础油添加剂的摩擦学性能,借助JSM3010型扫描电子显微镜及EDS测试分析钢球磨痕的表面形貌和成分组成,研究了添加剂的作用机制.结果表明:添加剂的引入明显改善了基础油的摩擦学性能,添加剂粒子通过吸附、填充、微滚珠以及熔融铺展作用降低钢球磨损,并对磨损表面进行一定的修复;硅酸盐粉体和纳米铜表现出良好的协同抗磨效应,复合添加剂的极压抗磨性能优于硅酸盐粉体或纳米铜单独作为添加剂.     

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.     

油溶性纳米铜的制备、表征及其对SF15W/40汽油机油摩擦性能的影响

采用界面生长法,以醋酸铜为母体,抗坏血酸(Vc)为还原剂,吐温-85为修饰剂,正丁醇为生长剂,合成了粒径约15.5 nm的油溶性球形纳米铜粉;通过X-射线衍射(XRD)和透射电子显微镜(TEM)对纳米铜粉进行了表征;将其作为润滑油添加剂分散于SF15W/40汽油机油中制得纳米润滑油;通过高浓度激光粒度仪考察了纳米润滑油的分散稳定性;通过UMT-Ⅱ摩擦磨损实验机考察了纳米润滑油的摩擦学性能;采用扫描电子显微镜(SEM)分析了磨损表面形貌.结果表明:纳米铜粉在润滑油中具有优异的分散稳定性;纳米铜粉显著改善了SF15W/40汽油机油的润滑性能,其最佳添加量为0.8%.分析认为纳米铜在摩擦表面的划痕和犁沟处沉积并铺展成膜,从而改善了摩擦磨损性能.     

一种自修复功能添加剂的制备及性能研究

以有机钼作为自修复添加剂的主要功能成分,加入抗氧剂和适量的极压抗磨剂,制备一种摩擦副自修复功能添加剂;通过四球摩擦试验、齿轮台架试验考察其性能,使用扫描电镜(SEM)和X射线光电子能谱仪(XPS)等分析其作用机制。结果表明:该添加剂具有优良的减磨和摩擦副自修复性能;在中低负载下该自修复添加剂主要通过在摩擦副表面生成物理、化学吸附膜发挥减摩作用;随着负载的增加和温度的升高,添加剂中的有机钼和硫磷系极压抗磨剂组分发生分解并与摩擦副表面的金属反应生成二硫化钼、磷酸铁、硫化亚铁、三氧化钼等沉积物,从而发挥良好的润滑与抗磨作用;在高负载下,该自修复添加剂主要通过微流变作用实现磨损表面的平整与自修复。     

羟基硅酸镁/Ag纳米复合材料的金属磨损自补偿特性与机制

在MMU-10G型摩擦磨损试验机上考察共混羟基硅酸镁(简称P)/Ag复合纳米材料对45~#钢摩擦副的磨损自补偿性能,用EPMA-1600电子探针和X射线光电子能谱仪表征摩擦运行后的试样表面形貌、元素组成及其价态。结果表明,含质量分数30%Ag的共混羟基硅酸镁/Ag复合纳米粉体作为自补偿添加剂能够在45#钢表面形成自补偿膜层,可有效减小其在磨合阶段和稳定磨损阶段的磨损失重;其自补偿机制为,在摩擦热化学、力化学与物理作用下,P/Ag复合纳米润滑添加剂在45~#钢表面形成了主要由Fe_2O_3、Fe_3O_4、FeOOH、SiO_2、MgO、C、Ag组成的表面膜,该膜层的补偿与隔离作用,可降低金属的磨损;其减摩作用是自补偿膜层中的铁氧化物、石墨形态C、软金属纳米Ag的低剪切应力和纳米P的微滚珠效应协同作用的结果。     

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。     

Study of the Regenerated Layer on the Worn Surface of a Cylinder Liner Lubricated by a Novel Silicate Additive in Lubricating Oil

Some special silicate particles as additives in lubricating oil have shown a certain self-repairing function for the rubbing pairs of industrial equipment in recent R&D of extreme pressure antiwear additives. This article introduces an investigation on the regenerated layer on the worn surface of a practical cylinder liner lubricated by lubricating oil with a silicate additive using some advanced techniques like transmission electron microscopy (TEM), atomic force microscopy (AFM), nano-hardness tester, scanning electron microscopy (SEM), auger electron spectroscopy (AES), and Raman spectroscopy. The basic formula of the mineral in the silicate additive is Al₄[Si₄O₁₀](OH)₄. Through some macro- and microanalyses, it was found that the silicate additive showed an obvious improving effect on their friction surface and self-repairing function. The roughness of the worn surface could be decreased greatly to several tens of nanometers, and its hardness was still above 10 GPa. The worn surface with some pits and cracks had been covered by a transparent regenerated layer, and the wear of cylinder liners was maintained at almost zero-wear level on average. The mechanism of the self-repairing function was approached. It was revealed that the silicate additive was acting as a catalyst to promote a series of complex tribochemical reactions to form a regenerated layer with amorphous carbon structure on the worn surface under high-friction temperature and pressure in the friction and wear process.     

Cr12MoV钢表面磁控溅射TiB2-TiN薄膜的摩擦磨损性能

采用磁控溅射技术在淬火态Cr12MoV表面制备SiC/TiN、SiC/TiB2-TiN薄膜(SiC为中间层),研究TiN、TiB2-TiN薄膜的组织结构和摩擦磨损性能。结果表明,SiC薄膜与基材和TiN、TiB2-TiN薄膜间都具有明显的且呈梯度的元素扩散,界面结合良好。在水润滑条件下与钢球对摩时(载荷0.5 N,时间0.5 h),TiN薄膜、TiB2-TiN薄膜具有良好摩擦磨损性能,其平均摩擦因数分别为0.33、0.31,低于淬火态Cr12MoV的0.45,磨损速率分别为2.0×10-8和1.5×10-8mm3/(N.m),低于淬火态Cr12MoV的8.66×10-7mm3/(N.m),其中在水润滑条件下TiB2-TiN薄膜比TiN薄膜具有更好的摩擦磨损性能。     

聚氨酯/TiO2纳米复合材料冲蚀磨损特性研究

以纳米TiO2作为填料,制备耐磨蚀聚氨酯纳米复合材料.用相对抗磨损性法评价了聚氨酯纳米复合材料的冲蚀磨损性,通过扫描电镜观察聚氨酯纳米复合材料的磨损形貌,尝试解释纳米TiO2增强聚氨酯复合材料抗含沙冲蚀磨损性能的机理.试验结果表明,纳米粒子均匀分散于聚氨酯中,使聚氨酯弹性体耐磨蚀性得以提高.聚氨酯/TiO2纳米复合材料的抗冲蚀磨损性能分别是45#钢的10.67倍,2Cr13钢的6倍,纯聚氨酯的1.28倍,TiN/聚氨酯复合材料的1.09倍.     

Benzimidazolyl phosphates as anti‐wear additives in poly(ethylene glycol) for steel/steel contacts

Four novel benzimidazolyl phosphates (BPs) were synthesized and evaluated as anti‐wear additives in poly(ethylene glycol) for steel/steel contacts. The friction experiments were carried out on an Optimol SRV‐I oscillating reciprocating friction and wear tester (SRV) both at room temperature and high temperature. The worn surfaces of the steel discs were analysed by JSM‐5600LV scanning electron microscope and PHI‐5702 multifunctional X‐ray photoelectron spectrometer. It was indicated that poly(ethylene glycol) with 2 wt% BP additives had better friction‐reducing and anti‐wear properties than the commercial lubricant additive, tricresyl phosphate. Excellent tribological performance of BPs could be ascribed to the formation of high quality boundary films that consisted of the ordered adsorption films and tribo‐chemical reaction films. Copyright © 2013 John Wiley & Sons, Ltd.     

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。     

羟基硅酸铝润滑油添加剂对钢/铸铁摩擦副磨损性能的影响

采用球盘试验和销盘试验相结合的方法,研究了钢/铸铁摩擦副在不同油润滑条件下磨损性能的变化,考察了不同含量羟基硅酸铝添加剂的作用效果,采用扫描电镜、X射线衍射仪以及纳米压痕仪对试验样品进行了分析测试。结果表明,该金属陶瓷添加剂表现出显著的抗磨性能,提高了钢/铸铁摩擦副承载能力和使用寿命;随着添加剂含量的增加,抗磨作用更加明显,负磨损现象开始出现;该添加剂可以抑制凹坑和裂纹的扩展,从而使摩擦表面形貌得到改善,并通过改变摩擦表面层的结构使摩擦副的磨损性能得到显著提高。     

Investigation of anti-wear additives for low viscous synthetic esters: Hydroxyalkyl phosphonates

Various synthetic esters are widely applied as lubricating fluid to reduce friction and wear at tribological contact. Among them low viscous synthetic esters are expected to improve fuel efficiency by minimizing the fluid friction. These low viscous esters are composed of short-chain fatty acids. Therefore, low viscous synthetic esters are inherently polar molecules. Since efficiency of anti-wear additives decreases with increase of polarity of the base oil, new additive technology is requested.In this work, hydroxyalkyl phosphates [P(O)(OCHRCH₂OH)₃], and hydroxyalkyl phosphonates [P(OH)_n(OCHRCH₂OH)_3−n, where n=1,2] are proposed as novel anti-wear additives for polar synthetic esters. The anti-wear additives are evaluated under the boundary conditions. The additives prevent wear in polar esters, in which conventional anti-wear additives do not work at all. Interestingly, effects of substituent in additive molecule on anti-wear properties are found. Alkyl and aryl derivatives reduce wear remarkably, whereas allyl derivatives exhibit poor results. It is speculated that the anti-wear inefiiciency of allylic compounds is due to auto-oxidation of the additives.A facile preparative method for hydroxyalkyl derivatives characterizes the present additive system. They are prepared in situ by simply mixing phosphonic acid and substituted epoxides. Flexiblity of lubricant design can be made possible by the present additive system.     

硅酸盐粉体作为润滑油添加剂在金属磨损表面成膜机制

在润滑油中添加蛇纹石硅酸盐粉体,采用MM-200摩擦磨损试验机研究了45#钢-45#钢摩擦副磨损表面的自修复陶瓷膜层形成机制,借助SEM及EDAX测试分析自修复陶瓷膜层的表面形貌及表面成分组成。结果表明摩擦能量对硅酸盐添加剂在磨损表面形成自修复膜层有很大的影响:自修复膜层为氧化物陶瓷材料,主要成分来自于硅酸盐添加剂。在低载荷300 N时,摩擦因数减小,硅酸盐添加剂不能转移到磨损表面,不能形成自修复膜层,仅仅起到减磨作用。下试样的失重随磨损时间增加而增加;在试验时间为20 h时,试样失重达到最大值,随后试样的失重反而减小。在载荷为600 N、900 N,试验时间30 h摩擦磨损后,在金属表面形成自修复保护膜,磨损表面比较平整光滑,无明显的片层剥落和犁沟,摩擦发生在自修复陶瓷材料之间,摩擦因数增加。硅酸盐添加剂在机械剪切作用下变形,在金属的磨损表面上铺展,并且在摩擦磨损过程中不断向摩擦表面转移,形成了均匀光滑的自修复膜层。自修复膜层隔离了金属摩擦表面的直接接触,摩擦磨损发生在自修复膜层之间,有效地降低了金属的磨损。     

几种纳米添加剂在环境友好润滑剂中的摩擦化学特性

采用机械化学修饰法研制了三种纳米润滑添加剂,二硫化钼(MoS2)、聚四氟乙烯(PTFE)和氟化石墨(CxFy),考察了这些纳米级润滑剂在环境友好润滑剂中的摩擦化学特性。结果发现：这些纳米添加剂在环境友好润滑剂中具有较好的抗磨性能和良好的减摩性能;减摩性能优于常用的极压抗磨剂,其机理是在摩擦副表面形成迁移膜,起“滚动微轴承”的作用。     

Characteristic evaluation of friction and wear in the C-N and TiN coated gear

C-N films were deposited on the 20CrMo alloy steel substrate by the Plasma Source Ion Implantation (PSII) method and TiN films were coated on the same material by the Physical Vapor Deposition (PVD) method. It was found that friction coefficient of C-N coating were relatively lower than TiN coating. And with the load increased, the friction coefficients of C-N coating and TiN coating were both decreased. Then the author puts forward the test rig, working under the conditions of 1,800 rpm, 20 N·m for 100 h. The observations by microscope showed the wear reduced. The antiwearing performance enhanced prominently. But the TiN coated gear had a more serious friction phenomenon than C-N coated gear. This is caused by that coating of TiN, which was made at a high temperature about 500°C. The high temperature led to the substrate intenerated and the surface hardness had decreased from 850 HV to 630 HV. PSII method eliminates the tempering problem of the coating of C-N films, which had better wear resistance than TiN films. The friction and wear resistance of gears which coated by C-N films ameliorated significantly.