山高刀具助力首都航天机械公司高精高效生产

<正>未来的某一天,我们将会看到这样的景象:来自世界任何一个角落的用户都能享受到由中国的卫星导航系统所提供的定位、导航、授时服务。事实上,这个"未来"并不遥远,我国的第二代卫星导航系统——北斗卫星导航系统将在2020年之前把这个美丽的设想变成现实。     

Tribological Performance of Lubricating Greases Based on Calcium Carbonate Polymorphs Under the Boundary Lubrication Condition

In this article, we synthesized the calcium sulphonate grease (CSG) based on the calcite using the bright stock (150BS) as the base oil. In order to investigate the tribological performance of lubricating grease containing different calcium carbonate polymorphs under boundary lubrication condition, a calcium sulphonate complex grease (CSCG) based on the vaterite was used as a reference. An oscillating reciprocating friction and wear tester set at a series of applied loads and frequencies was adopted to evaluate the tribological performance under boundary condition. Results showed that the lubricating grease that was composed of crystalline calcite as the partial thickener had excellent friction-reducing and antiwear (AW) properties, regardless of the applied loads and frequencies. The vaterite in CSCG easily experienced a polymorph transformation into calcite or aragonite characterized by Raman spectroscopy. This polymorph transformation was attributed to the highly local friction temperature and activated hydrogen from water or acids oxidated in the rubbing process at high load or frequency. The physical polymorph transformation corresponded to the fluctuations of the friction coefficients, then contributed to the severe wear. XPS analysis indicated that two calcium sulphonate lubricating greases occurred a tribochemical reaction and boundary tribofilms consisted of CaCO₃, CaO, iron oxide and FeSO₄ were formed on the rubbing surfaces. The tribofilm formed by the introduction of the CSG that mainly depended upon the thickeners of calcite structure contributed to an excellent AW protection. The possible boundary friction mechanism for greases based on various calcium carbonate polymorphs was also proposed. Effect of calcium carbonate polymorphs on the tribological performance was discussed.     

N-月桂酰基谷氨酸的合成及作为润滑油添加剂的研究

采用月桂酰氯和谷氨酸在碱性溶液中反应制备出了N-月桂酰基谷氨酸。用红外光谱对其主要官能团进行了表征;考察了该物质作为润滑油添加剂对HVI350矿物基础油的生物降解性能的影响,并用四球摩擦磨损试验机考察了N-月桂酰基谷氨酸在HVI350矿物基础油中的摩擦磨损性能。结果表明：N-月桂酰基谷氨酸作为矿物油添加剂提高了矿物油的生物降解性能,并且具有良好的抗磨减摩性能和优良的防锈性,是一种环境友好型的多功能润滑添加剂。     

含石墨烯润滑油多孔聚酰亚胺摩擦学行为研究

多孔聚酰亚胺（PI）可以在孔隙中储存润滑油,当多孔PI作为摩擦壁面时孔隙内的润滑油会渗出实现润滑。为实现更优异的润滑效果,将石墨烯润滑油渗入多孔PI中,制备含石墨烯润滑油多孔PI。以氮化硅（Si3N4）为摩擦副,基于分子动力学原理建立Si3N4-多孔PI-Si3N4层结构以及多孔含油聚酰亚胺（PI/C）-润滑油膜-Si3N4层结构,模拟多孔PI与Si3N4之间的范德华能、剪切应力、相对浓度分布以及温度分布,分析石墨烯润滑油渗入后形成的含石墨烯润滑油多孔PI结构(PI/CG)对多孔PI润滑性能的影响,并通过试验验证了仿真结果。研究发现：在PI孔隙中浸入石墨烯润滑油后,PI材料的吸附能力变强、剪切应力减小、摩擦副间温度降低以及耐磨性提高;PI/CG可明显改善润滑效果,在摩擦磨损试验过程中的摩擦学性能优于PI/C。     

有机多硫化物润滑添加剂的制备及其摩擦学性能

合成一种有机多硫化物(OP),用红外光谱仪对其结构进行分析,采用四球摩擦磨损试验机及SRV试验机考察其在基础油PAO10中的摩擦学性能。结果表明:添加剂OP具有优良的极压性能,并且在微动摩擦磨损试验机中表现出良好的抗磨减摩作用。用X射线光电子能谱仪对试球表面分析可知,有机多硫化物与金属表面发生化学反应,生成了含硫边界润滑膜,从而起到极压抗磨减摩的作用。     

Tribological Performance and Transfer Behavior of Lubricating Oils at Head-Disk Interface under Volatile Organic Contamination

Tribological performance of head-disk interface (HDI) under volatile organic contamination was investigated using a contact start/stop (CSS) tester. Slider and disk surfaces were analyzed using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) after CSS tests. The CSS test results indicated that the friction forces were high and unstable under contamination. Transfer of lubricating oil onto the slider surface was detected after the CSS tests. The transfer amount of lubricating oil was revealed to be dependent on the chemical structure of the terminal group in the lubricating oil. Piperonyl (–CH₂−phe=(O)₂=CH₂) terminated AM3001 lubricating oil was lost more easily than two hydroxyl (–OH) terminated Tetraol lubricating oil, probably because of the weak attractive force of the piperonyl groups with carbon overcoat. TOF-SIMS chemical images indicated that the transferring behavior of the lubricating oil onto the slider surface during CSS tests was dependent on the chemical structure of volatile organic contaminants. The lubricating oil became built up on the slider surface when the dioctyl sebacate (DOS) pollutant used. In contrast, the lubricating oil distribution on the slider surface was uniform under a polydimethylsiloxane (PDMS) vapor. The different transfer behavior of lubricating oil onto the slider surface may be resulted from the changeable surface properties of slider and disk because of the coexistence with gaseous contaminants.     

镍基合金喷熔层摩擦学行为与机制的研究

采用热喷熔工艺制备了两种镍基合金喷熔层,并选用高锰钢、不锈钢作为对比材料,研究了镍基合金喷熔层的摩擦磨损性能。研究结果表明：镍基合金喷熔层具有良好的耐磨损性能和较低的摩擦系数。镍含量对喷熔层的摩擦学性能有显著影响,高镍含量的镍基合金,其耐磨性能明显优于低镍含量的镍基合金。在低速轻载条件下,镍基合金喷熔层的磨损机理为微观犁削;高速重载时,表现为粘着磨损和磨料磨损,其中高镍含量的喷熔层表面形成了致密的转移膜,有效地降低了磨损率。     

粘结固体润滑涂层在油润滑条件下的摩擦学性能

为了探讨粘结MoS2基固体润滑涂层在油润滑条件下的抗磨减摩性能,采用MHK-500型摩擦磨损试验机对粘结MoS2基固体润滑涂层在4种常用油(液体石蜡、RP-3煤油、4050滑油和CD-40柴油)润滑下的摩擦磨损性能进行了研究,考察了速度和载荷对润滑涂层在4种不同的常用油润滑下的摩擦磨损性能。结果表明,在低载荷(320N)试验条件下,4种常用油润滑下涂层的耐磨性比干摩擦下得到显著的提高,摩擦因数从0.12降低到0.08左右;但在高载荷(1100N)下,油润滑对涂层的摩擦磨损性能没有明显的改善。只有在合适的载荷下,固/油复合润滑技术可明显改善摩擦副的润滑性能。     

纳米TiN润滑油添加剂的摩擦学性能研究

使用四球摩擦试验机研究纳米TiN作为润滑油添加剂的摩擦学性能, 并利用磨斑测量系统、激光共聚焦显微镜OLS1100和EDS测试分析其磨损特性和自修复性能。实验结果表明：纳米TiN作为润滑油添加剂具有良好的抗磨减摩和自修复性能;在润滑油中加入质量分数为05%的纳米TiN添加剂和10%的PEG 200分散剂,可达到最佳的抗磨减摩效果。在高载荷下,纳米TiN润滑油的自修复比表面抛光的效果更好。     

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。     

N-酰基苯丙氨酸的合成及其在水基中润滑和防锈性能研究

将脂肪酸酰氯和苯丙氨酸在碱性溶液中反应得到的N-酰基苯丙氨酸，用红外光谱对其结构进行表征；用四球摩擦磨损试验机考察了N-酰基苯丙氨酸以三乙醇胺为助溶剂时在水溶液中的摩擦磨损性能，并用俄歇电子能谱研究了磨斑表面边界膜的化学组成和元素分布。结果表明：N-酰基苯丙氨酸的水溶液表现出很好的抗磨和减摩特性，这可能是N-酰基苯丙氨酸三乙醇胺盐中的极性基团吸附在钢球的表面，长碳链疏水性的烃基在金属表面形成较厚的保护膜，在较高载荷运行下，发生化学反应形成高强度的摩擦化学反应膜；N-酰基苯丙氨酸三乙醇胺盐还有较好的防锈性。经细菌试验表明其具有较好的抗菌能力。     

一种纳米氟硼酸盐润滑油添加剂的制备及其摩擦学性能

采用机械化学法制备出经偶联剂表面修饰的氟硼酸盐纳米微粒。借助TEM、XRD对表面修饰纳米氟硼酸盐微粒进行了表征,并利用四球摩擦试验机对其用作润滑油添加剂的摩擦学性能进行了评价,试验条件为载荷100~700N,转速1200r/min,时间10min。结果表明所制备的表面修饰氟硼酸盐微粒平均粒径小于100nm,且分散性好;以其作为聚α-烯烃合成油添加剂,当添加量为0.9%(质量分数)时,在载荷300N下,可降低摩擦因数18%,减小磨斑直径19%,且具有良好的极压抗磨性能。     

Molecular Behavior of Room-temperature Ionic Liquids under Lubricating Condition

The molecular behavior of room-temperature ionic liquids (RTILs) under lubricating condition was analyzed using fourier transform infrared spectroscopy equipped with a pin-on-disk tribometer to simultaneously measure the friction force, normal load, and IR spectrum. When 1-metyl-3-butylimidazolium trifluoromethanesulfonate ([BMIM]OTf), which is miscible with water, was used as a lubricant, the water content increased with time, and the ratio of water to cation remained constant even though the film thickness reduced under the lubricating condition at a load of ~25 N. When 1-metyl-3-butylimidazolium tetrafluorophosphate ([BMIM]PF₆), which is water-insoluble, was used as a lubricant, the water content was quite small and increased slightly with time, and the ratio of water to cation also remained constant even when a normal load of ~25 N was applied. The SUJ2 pin surface showed oxidative discoloration after the friction test using [BMIM]OTf, but there was little change in color when[BMIM]PF₆ was used. XPS results indicated that iron oxide, chromium oxide and sulfate were observed on the worn pin surface using [BMIM]OTf and the CaF₂ disk. However, iron oxide and iron phosphate were observed for the worn pin surface using [BMIM]PF₆ and the CaF₂ disk. These results suggest that the amount of water contained in the RTILs as well as window materials have a significant effect on the tribo-chemical reaction of RTILs.     

TiAlN涂层及微观组织结构研究

通过改变工艺参数,采用非平衡磁控溅射法在硬质合金基体上制备Ti Al N涂层来研究涂层微观结构的变化规律。经表面和断口形貌的扫描电镜结果显示,增加主因素偏压,涂层表面趋向光滑平整,结构趋向致密,表面的大颗粒数量明显减少。EDS能谱分析表明,涂层元素的含量受偏压和N2流量影响较大。XRD分析发现,膜层中有Ti Al N系和Ti N系的物相结构,Ti N/Ti Al N多层涂层主要从(111)晶面择优取向生长。     

Tribological Performance of Laser-Textured Polyoxymethylene under Boundary Lubricated Sliding Condition

Micro texturing was fabricated on polyoxymethylene surfaces using laser texturing, and the tribological characteristics were studied. Micro texturing was proven to be very effective in lowering the coefficient of friction, regardless of the texturing depth used in this study. Laser texturing was practical and efficient owing to its fast process time with reasonable machined shapes. An optimum aspect ratio and area density of texturing would exist under the conditions used in this study. Wear of polyoxymethylene was negligible.     

润滑条件对纳米SiO2填充尼龙复合材料摩擦学性能的影响

利用MM-200磨损实验机在干摩擦、水润滑和油润滑等条件下，研究了润滑条件对含量为10％的纳米SiO2填充尼龙1010复合材料与45^#钢对磨时的摩擦学性能的影响，并利用扫描电子显微镜对纳米SiO2-PA1010复合材料的磨损表面和磨损机理进行了观察和分析。结果表明水润滑时，纳米SiO2-PA1010复合材料的摩擦因数比在干摩擦时有一定程度的降低，但磨损量却比干摩擦时增加了很多；而在油润滑时，摩擦因数和磨损量均比干摩擦和水润滑时降低了许多；复合材料的磨损机制也随着润滑条件的不同发生了相应的变化。     

PTFE对复合镀层摩擦特性的影响

研究了PTFE添加量对Ni基电刷镀PTFE复合镀层的摩擦特性和磨损机制的影响.采用扫描电镜、X射线衍射仪和能谱仪分析了摩擦前后的磨损表面的形貌、组织和成分变化.结果表明:PTFE添加量对复合镀层的组织和摩擦特性有较大的影响.当PTFE体积分数为3%和4%时,复合镀层的摩擦因数最小;当PTFE体积分数为2%时,复合镀层的耐磨性最好.在磨损面上富含PTFE复合层的形成和面积随PTFE添加量的变化影响了复合镀层的摩擦特性及其磨损机制.     

TiAlN纳米复合涂层的技术进展

综合介绍了国内外TiAlN涂层技术的发展现状和TiAlN涂层的性能特点、PCD制备工艺以及今后的发展趋势和研究方向;重点评述了高Al含量TiAlN超硬涂层、异质多层膜纳米复合TiAlN涂层和多元合金增强涂层技术的最新进展;指出了TiAlN涂层刀具在精密模具和汽车零部件加工中的重要作用。     

Monitoring of Wear Characteristics of TiN and TiAlN Coatings at Long Sliding Distances

TiN and TiAlN thin hard coatings have been widely applied on machine components and cutting tools to increase their wear resistance. These coatings have different wear behaviors, and determination of their wear characteristics in high-temperature and high-speed applications has great importance in the selection of suitable coating material to application. In this article, the wear behavior of single-layer TiN and TiAlN coatings was investigated at higher sliding speed and higher sliding distances than those in the literature. The coatings were deposited on AISI D2 cold-worked tool steel substrates using a magnetron sputtering system. The wear tests were performed at a sliding speed of 45 cm/s using a ball-on-disc method, and the wear area was investigated at seven different sliding distances (36–1,416 m). An Al₂O₃ ball was used as the counterpart material. The wear evolution was monitored using a confocal optical microscope and surface profilometer after each sliding test. The coefficient of friction and coefficient of wear were recorded with increasing sliding distance. It was found that the wear rate of the TiAlN coating decreases with sliding distance and it is much lower than that of TiN coating at longer sliding distance. This is due to the Al₂O₃ film formation at high temperature in the contact zone. Both coatings give similar coefficient of friction data during sliding with a slight increase in that of the TiAlN coating at high sliding distances due to the increasing alumina formation. When considering all results, the TiAlN coating is more suitable for hard machining applications.     

火焰喷涂PA1010/n-SiO2复合涂层干摩擦磨损性能

利用火焰喷涂法制备PA1010/n-SiO2复合涂层,并采用均匀试验设计方法研究涂层在干摩擦条件下同GCr15 钢环配副时的摩擦学性能;利用SPSS 12.0统计软件对试验结果进行回归分析, 建立涂层摩擦系数和磨损质量损失同pv值 (摩擦载荷与摩擦速度的乘积)相关性的数学模型;利用示差扫描量热仪(Differential scanning calorimetry, DSC)和扫描电子显微镜(Scanning electron microscope, SEM)对复合涂层的热性能和磨损表面形貌进行分析。结果表明,n-SiO2的加入能明显提高涂层的结晶性能、耐磨性能。当n-SiO2含量为1.5%时,复合涂层摩擦磨损性能最佳,在试验条件下磨损质量损失降低近4倍,摩擦因数降低23％,跑合期缩短44％,复合涂层与GCr15钢环对磨时的磨损机理主要为疲劳磨损和轻微的粘附 磨损。