菜籽油润滑条件下TiN涂层摩擦学特性*

为探究TiN涂层在油润滑条件下的摩擦磨损性能,通过磁控溅射技术在AISI304不锈钢上制备TiN涂层,借助扫描电镜、纳米划痕仪、XRD和摩擦磨损试验机探究不同氮通比下TiN涂层的微观结构、力学性能及其在植物菜籽油润滑下的摩擦学性能。实验结果表明：在氮通比为0.45下制备的TiN涂层具有最致密的晶状结构,且力学性能最优;在菜籽油润滑下,随着氮通比的增大TiN涂层摩擦因数和磨损率呈现先降低后增加的趋势,在氮通比为0.45时两者均最小。XPS分析表明,TiN涂层表面存在的氧化层,增加了菜籽油在涂层表面的润湿性,从而更好地形成润滑膜而起到润滑特性。与橄榄油、聚α烯烃(PAO6)基础油、5W40润滑油3种润滑介质相比,TiN菜籽油润滑下涂层表现出更优的润滑性能。     

不同基体CrN/CrCN多层涂层海水环境摩擦学性能研究*

为研究不同基体材料对CrN/CrCN多层涂层在海水环境下摩擦学性能的影响,采用多弧离子镀技术在H65铜合金、TC4钛合金和316L不锈钢基体上沉积CrN和CrN/CrCN多层复合涂层,通过XRD、SEM等技术对涂层的结构进行表征,通过结合力、硬度测试和摩擦磨损试验分析涂层在大气环境和海水环境下的力学性能和摩擦学性能。结果表明:CrN/CrCN多层涂层的内应力相对于CrN明显减小,且硬度相对CrN涂层较高;TC4钛合金为基体的涂层结合力较好且涂层硬度较高;在海水环境下涂层的摩擦因数相对于大气环境都有较大幅度下降,其中,以TC4钛合金和316L不锈钢为基体的涂层摩擦因数较小;以H65铜合金为基体的2种涂层在海水中的磨损率高于大气中,而以TC4合金、316L不锈钢为基体的CrN/CrCN多层涂层在海水环境下的磨损率低于大气环境;TC4钛合金为基体的CrN/CrCN多层涂层在海水环境下具有最低的磨损率,表明TC4钛合金更适合作为海水环境下CrN/CrCN多层涂层耐磨的基体材料。     

CrN和CrN/Ag涂层的真空高温摩擦磨损性能*

为改善涂层在真空、高温等苛刻条件下的摩擦学性能,利用中频直流磁控溅射技术在硅片和316L不锈钢上沉积了CrN和CrN/Ag涂层,利用扫描电镜、透射电镜和X射线衍射仪对涂层的成分及相结构进行了表征,通过划痕测试仪、纳米压痕仪和摩擦磨损试验机测试了涂层的力学及摩擦学性能。结果表明：添加Ag元素以后,CrN/Ag涂层硬度及承载能力有所减小,但结合强度增加;真空高温环境下CrN与CrN/Ag涂层摩擦因数随温度升高呈下降趋势,其中CrN涂层通过软化镀层减小剪切强度和阻力,从而减小摩擦因数,CrN/Ag涂层主要通过高温产生的热驱动力诱导表面Ag润滑膜的形成来减小摩擦因数;CrN涂层依靠自身剪切特性参与摩擦,而CrN/Ag涂层在真空高温下具有自润滑和持续润滑性能,作为自润滑零部件具有潜在的应用价值。     

沉积温度对CrN涂层干摩擦及大豆油润滑下摩擦学性能的影响

为探究沉积温度对CrN涂层摩擦学性能的影响,同时寻找适合CrN涂层润滑的绿色润滑剂,采用磁控溅射技术在不同温度下制备CrN涂层。利用X射线衍射仪、扫描电子显微镜、AFM原子力显微镜、划痕仪、纳米压痕仪和摩擦磨损试验机评价涂层的微观结构、力学性能,以及在干摩擦及大豆油润滑条件下的摩擦磨损性能。结果表明：在250 ℃下沉积的CrN涂层具有最致密的晶状结构,且力学性能最优。摩擦试验结果显示,在干摩擦和大豆油润滑下250 ℃下沉积的CrN涂层表现出最优的摩擦学特性。XPS分析表明,由于摩擦的存在,大豆油会在涂层表面发生摩擦化学反应并生成一层化学吸附膜,从而能有效减轻涂层的摩擦和磨损。250 ℃下沉积的CrN涂层具有最优的力学及摩擦学性能,且大豆油极为适合CrN涂层的润滑。     

几种润滑油添加剂与等离子渗氮层的交互作用研究

研究等离子渗氮GCr15钢与GCr15钢基材在添加硫化异丁烯(SO)、磷酸三甲酚脂(TCP)、硫代磷酸胺盐(SPN)、二烷基二硫代磷酸锌(ZDDP)的PAO润滑下的摩擦磨损性能.利用脉冲直流等离子渗氮炉对GCr15钢进行离子渗氮处理,采用X射线衍射(XRD)分析离子渗氮层的相组成,利用显微硬度计测量渗氮前后的表面硬度值,在四球摩擦磨损试验机上考察GCr15钢渗氮处理前后在添加SO、TCP、SPN、ZDDP的PAO润滑下的摩擦磨损性能,通过扫描电子显微镜(SEM)和能量散射谱(EDS)分析其摩擦学作用机制.结果表明:离子渗氮处理明显提高了GCr15钢的表面硬度值和摩擦磨损性能;含硫、磷添加剂具有良好的减摩性能和抗磨性能,并能与渗氮层发生交互作用,尤其是TCP的效果最明显.     

青铜-石墨热喷涂层在干摩擦和水润滑条件下的摩擦磨损性能

在MM-200摩擦磨损试验机上研究了青铜-石墨热喷涂层在干摩擦和水润滑条件下的摩擦磨损性能,采用扫描电镜(SEM)对磨损表面形貌进行了观测和采用X射线能谱分析(XPS)分析了涂层成分。结果表明,在水润滑条件下涂层摩擦因数和磨损率均低于干摩擦条件下;在水润滑条件下磨损机制为轻微磨粒磨损和犁削磨损,在干摩擦下主要是较为严重的粘着磨损和犁削。这是由于水润滑降低了摩擦副界面温度,提高了石墨润滑膜的韧性,改善了润滑效果,从而阻止了粘着磨损的发生,水还促进了钢偶件表面致密氧化膜的形成,从而减轻磨损。因此水润滑对涂层磨损性能有较大影响。     

不同涂层在甘油环境下的摩擦学性能对比研究

为提高甘油环境下摩擦副的抗磨能力,采用磁控溅射技术在单晶硅P(111)、316L不锈钢上分别制备DLC、CrN、TiN涂层。分别在大气及甘油环境下,利用多功能摩擦磨损试验机对涂层摩擦磨损性能进行对比研究,分析摩擦因数、磨损率及磨痕形貌的变化规律,并对比分析甘油环境中不同涂层与涂层配副在重载高速下摩擦力矩变化规律。结果表明:DLC涂层在大气环境下具有最优的减摩抗磨性能,DLC涂层和CrN涂层在甘油环境下均具有优良的减摩耐磨性能;在100 N载荷下DLC-CrN涂层配副在甘油环境下在整个测试过程中摩擦力矩比较小,且样块表面均无明显的磨损及划痕,表明DLC-CrN涂层配副在甘油环境及重载高速工况下具有优异的摩擦学性能。     

磷嗪对Ti6Al4V/钢摩擦副摩擦磨损性能的影响

采用SRV型微动摩擦磨损实验机考察Ti6Al4V-钢摩擦副在磷嗪(X-1P)润滑下的摩擦磨损性能,并利用扫描电子显微镜和X射线光电子能谱仪分析Ti6Al4V磨斑表面形貌和典型元素的化学状态。结果表明,X-1P作为Ti6Al4V-钢摩擦副的润滑剂,具有很好的润滑性能;摩擦因数随载荷的增加变化不显著,磨损率随载荷的增加逐渐增大;频率和振幅明显影响摩擦学性能,磨损率随频率的增加逐渐减小,随振幅的增加逐渐增大;在Ti6Al4V-钢摩擦副中,X-1P由于含有极性元素F、P,Ti6Al4V的磨损表面主要发生腐蚀磨损,其磨损机制为X-1P在磨损表面发生摩擦化学反应,形成一层含O、C、F、N、P的保护膜以及金属氟化物,从而起到抗磨减摩作用。     

超音速火焰喷涂锡青铜-钢基双金属材料摩擦性能

采用超音速火焰喷涂QWFSn8Zn3粉末制备钢背双金属材料。研究不同润滑介质、不同表面粗糙度和不同摩擦载荷对超音速喷涂锡青铜-钢基涂层摩擦性能的影响。分析锡青铜涂层的磨损形貌和磨损机制。研究结果表明:抗磨液压油润滑条件下,涂层有最小的摩擦因数0.093,30#润滑油、液体石蜡和固体MoS2润滑下涂层摩擦因数分别为0.099、0.107和0.099;随表面粗糙度减小,喷涂锡青铜-钢基涂层摩擦因数逐渐减小;随着摩擦载荷的增加,喷涂层摩擦因数逐渐减小;不同润滑介质条件下,涂层存在磨粒磨损、黏着磨损和疲劳磨损共同作用的磨损机制。     

水热法油酸修饰纳微米硼酸锌的制备及摩擦学性能研究

以硼砂和硫酸锌为原料经水热法制得硼酸锌;通过场发射扫描电镜、X射线衍射、热重分析和红外分析表征硼酸锌的结构.结果表明,分散介质的变化对硼酸钙的形貌有一定的影响.将油酸修饰的硼酸锌分散于聚α-烯烃( PAO)中,利用SRV 1型微动摩擦磨损试验机考察其摩擦学性能,并分析摩擦机制.结果表明:在一定水热时间下制备的油酸修饰硼酸锌,能有效降低PAO润滑时45#钢的摩擦因数和磨损率;XPS分析显示,油酸修饰硼酸锌作为润滑添加剂时,在磨痕表面形成了含B、Zn和Fe的摩擦膜.     

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.     

The Effect of FeS Solid Lubricant on the Tribological Properties of Bearing Steel under Grease Lubrication

In order to improve the tribological properties of 52100 steel under grease lubrication, FeS solid lubricant was used in two ways. Low-temperature ion-sulfurization technology was utilized to prepare solid lubricant iron sulfide (FeS) films on the surface of 52100 steel, and FeS particles were mixed into the lithium grease as additive. The friction and wear properties were examined systematically on a “ball-on-disc” testing machine. The results showed that the tribological properties of bearing steel under grease lubrication can be improved either by using ion-sulfurization technique or by adding FeS microparticles into the grease. The tribological performance of sulfurized surface lubricated by grease is better than that of a plain surface lubricated by grease containing FeS microparticles at lower load and speed. The plain surface lubricated by the grease containing FeS micropaticles possesses better antiwear property under harsher conditions. The mechanism of the experimental results is discussed in detail.     

Comparison of the effects of ionic liquid and anti‐wear additives on the tribological properties of Cr―Mo―N coatings

Cr―Mo―N coating was prepared by magnetron sputtering, and its crystallinity and phase structure were analysed by X‐ray diffraction. The tribological properties of the coating separately lubricated with L‐P106 ionic liquid was compared with poly‐alpha‐olefin (PAO) and PAO‐containing MoDTP and ZnDTP additives with a ball‐on‐disc reciprocal friction and wear tester. It was found that the tribological properties of as‐prepared Cr―Mo―N coating vary with varying lubricant systems. Namely, the results indicated that the L‐P106 has better friction‐reducing and wear resistance properties than that of MoDTC and ZnDTP. The analyses indicated that Cr―Mo―N coatings and lubrication films can be considered as a solid–liquid duplex lubricating systems. Copyright © 2014 John Wiley & Sons, Ltd.     

表面粗糙度对Al2O3增强Y-TZP陶瓷材料生物摩擦学特性的影响

采用销-盘式摩擦磨损试验机研究了氧化铝增强氧化锆陶瓷(ADZ)的表面粗糙度对ADZ/316L不锈钢摩擦副的摩擦磨损性能的影响。结果表明:在小牛血清润滑下,随着陶瓷表面粗糙度的降低,ADZ陶瓷和316L不锈钢的摩擦因数和磨损率均呈降低趋势。但是对于表面粗糙度最高的陶瓷,由于Fe转移膜的物理吸附,出现了“负磨损”现象。     

油润滑下MoSi2材料的摩擦磨损性能

运用M-200型摩擦磨损试验机测定了油润滑条件下MoSi2与45调质钢、45淬火钢和CrWMn钢配对时的摩擦磨损性能，采用扫描电镜和微探针分析了摩擦副表面的形貌，探讨了磨损机理：结果表明：采用20号机械油润滑可有效地降低MoSi2材料的磨损率及摩擦因数；与低硬度的45调质钢和45淬火钢对摩时，MoSi2材料的主要磨损机制为晶间断裂、疲劳断裂、轻微粘着磨损和磨粒磨损；MoSi2材料与高硬度的CrWMn钢对摩时，主要磨损机制表现为粘着磨损、微犁削式磨粒磨损，并在偶件表面材料凸点的前端形成楔块。     

Super low friction of DLC applied to engine cam follower lubricated with ester-containing oil

This paper presents a material combination that reduces the friction coefficient markedly to a superlow friction regime (below 0.01) under boundary lubrication. A state approaching superlubricity was obtained by sliding hardened steel pins on a hydrogen-free diamond-like carbon (DLC) film (ta-C) lubricated with a poly-alpha-olefin (PAO) oil containing 1 mass% of an ester additive. This ta-C/steel material combination showed a superlow friction coefficient of 0.006 at a sliding speed of 0.1 m/s. A hydrogencontaining DLC coating/steel combination also showed a lower friction coefficient in air than a steel/steel combination, 0.1 vs. 0.8, but no large reduction was observed when the sliding surfaces were lubricated with ordinary 5W-30 engine oil and the PAO oil containing an ester additive. The friction coefficient of the hydrogen containing DLC/steel combination lubricated with the PAO containing an ester additive was above 0.05. On the other hand, the superlow friction performance demonstrates that the rolling contact friction level of needle roller bearings can be obtained in sliding contact under a boundary lubrication condition. It is planned to apply this advanced DLC coating technology to valve lifters lubricated with a newly formulated engine oil in actual mass-produced gasoline engines. A larger friction reduction of more than 45% is expected to be obtained at an engine speed of 2000 rpm.     

Tribological properties of plasma nitrided stainless steel against SAE52100 steel under ionic liquid lubrication condition

1Cr18Ni9Ti stainless steel was modified by plasma nitriding. The phase composition of the plasma nitrided layer was examined by means of X-ray diffraction. The friction and wear properties of the modified and unmodified 1Cr18Ni9Ti stainless steel specimens sliding against SAE52100 steel under the lubrication of ionic liquid of 1-ethyl-3-hexylimidazolium hexafluorophosphate (L-P308) and poly α-olefin (PAO) were investigated on an Optimol SRV oscillating friction and wear tester, with the interactions among the modified surface layer and the ionic liquids and PAO to be focused on. The morphologies of the worn surfaces were observed using a scanning electron microscope. The chemical states of several typical elements on the worn surfaces of the modified steel surfaces were examined by means of X-ray photoelectron spectroscopy. Results showed that the modified sample had better anti-wear abilities than the unmodified one, but the modified sample had a slightly higher friction coefficient than the untreated one. This was partly attributed to the change in the hardness and phase composition of the stainless steel surfaces after plasma nitriding and tribochemical reactions between the steel and the lubricant. The resultant surface protective films composed of various tribochemical products together with the adsorbed boundary lubricating film contributed to reduce the friction and wear.     

不同润滑液下的Al2O3增强Y-TZP陶瓷/316L不锈钢生物摩擦学特性

采用销-盘式摩擦磨损试验机研究了氧化铝增强氧化锆(ADZ)陶瓷材料/316L不锈钢摩擦副在去离子水和小牛血清2种不同介质润滑下的生物摩擦磨损行为,并利用SEM观察了磨损表面形貌。结果表明:与去离子水相比,在小牛血清润滑条件下ADZ陶瓷的摩擦因数和磨损率降低。在去离子水润滑条件下ADZ陶瓷材料的磨损为轻微磨损,相应的磨损机制为塑性变形和微犁削;而在小牛血清润滑条件下,ADZ陶瓷材料的磨损为微量磨损,磨损过程类似抛光作用。