外部因素对工程陶瓷材料摩擦磨损特性影响的研究

除材料本身特性外,外部因素如载荷、滑动速度、滑行距离、温度、环境以及摩擦方式等因素同样影响材料的摩擦磨损特性。本文探讨了外部因素对结构陶瓷摩擦磨损的影响,旨在促进在特定工况下正确使用相应的陶瓷材料作为摩擦学部件。     

热等静压氮化硅陶瓷、钴铬15及钼50钢摩擦学研究

介绍了国内外陶瓷材料研究现状及发展趋势。作为耐高温、耐腐蚀等复合摩擦副材料，介绍了热等静压烧结的氮化硅陶瓷、钴铬15及钼50高速合金钢的摩擦学性能。对陶瓷材料的润滑及摩擦化学反应对陶瓷材料摩擦学特性的影响进行了初步探讨。     

Al2O3陶瓷材料的摩擦学研究进展

氧化铝陶瓷刀具材料具有硬度高、耐磨性好、高温性能优良、抗黏结和抗扩散能力强、化学稳定性好等特点,广泛应用于高速切削和切削难加工材料领域。从陶瓷材料晶粒尺寸与摩擦学性能相关性、复相氧化铝陶瓷材料的摩擦学性能和氧化铝陶瓷的磨损机制3个方面,综述氧化铝陶瓷材料摩擦学研究进展,以期为新型高品质氧化铝陶瓷刀具材料的开发提供帮助。细化晶粒和组分复合化是提高陶瓷材料的强度和断裂韧性,进而提升其摩擦学性能的有效途径,但目前氧化铝陶瓷摩擦学研究主要是基于晶粒尺寸为600 nm以上的单相陶瓷和基体晶粒尺寸为1μm左右的复相陶瓷材料,对纳米/超细晶(500 nm以下)氧化铝陶瓷材料的研究是未来的研究方向。     

高技术结构陶瓷材料在大口径工业阀门上的应用

在传统的金属阀门中引入新型增韧陶瓷材料，采用新型陶瓷材料制作阀门的密封部件、易损部件及过流面，并与金属有机结合，利用陶瓷自身的高硬度和耐腐蚀的特性，提高阀门使用寿命，拓宽阀门使用领域。     

空间摩擦学在卫星活动部件轴系的应用研究现状及发展

由于空间环境和使用条件的特殊性,空间活动部件涉及的摩擦学问题复杂。由卫星在轨失效统计分析和宇航任务所提出的新要求表明,空间活动部件对空间摩擦学应用研究的需求非常迫切。将空间摩擦学的主要研究内容分为以下4个方面:空间精密轴系长寿命润滑技术、长寿命润滑工艺技术、关键材料应用技术和润滑寿命试验及评估技术,对每个方面所包含的具体研究内容、研究现状以及在长寿命高可靠摩擦学设计中的作用进行了详细的介绍。结合空间任务的需求以及存在的关键问题,为有针对性的开展相应研究,提出了空间摩擦学及应用研究需要深入开展的研究方向。     

新型陶瓷材料的开发及应用

概要论述了新型陶瓷材料应用及发展,探讨了传统陶瓷材料向现代功能陶瓷材料转变的过程的同时,还重点讨论了新型陶瓷材料在现代机械工业,特别是在动力机械、热能传递、加工工具及轴承等运动部件上的实际应用及发展趋势。     

空间装备摩擦学部件服役工况分析

航天任务的复杂程度和时限逐步加大,对空间装备零部件的可靠性和寿命要求越来越高,空间装备中各机械摩擦部件能否正常运转和达到预期寿命已成为航天任务能否顺利完成的关键因素。对主要空间装备摩擦学部件的运动工况进行总结,指出空间摩擦学部件涉及较宽的速度和载荷范围,且常处于连续工作、多次"启-停"或间歇操作等复杂的运动状态,并归纳分析直接影响摩擦、磨损和润滑问题的主要空间环境因素,即高真空、快速温变和极端温度、强辐射、原子氧、微重力以及微流星和空间碎片,提出未来我国可以从空间环境效应以及空间润滑材料的设计制备两方面进行深入研究,从而大大提高空间装备摩擦学部件的服役寿命和可靠性。     

摩擦小、磨损率低的陶瓷材料

日本五十铃陶瓷研究所已研制成功一种摩擦小、磨损率低可用于制造汽车发动机部件和轴承等机械零、部件的陶瓷材料.这种新陶瓷材料是将粒径小于1μm的超细铁化合物粒子分散在氮化硅基体中制成的.     

赴美摩擦学技术考察报告(续)

近几年来,该院对工程陶瓷材料的摩擦学特性研究得很深入,发表了许多高水平论文。如氯化铝陶瓷在干滑动、非反应性液体以及反应性液体的不同情况下的三维磨损图谱,在国际上影响很大。他们详细研究了这类材料的磨损系数与速度和载荷,速度和温度,速度和时间,载荷和温度,载荷和时间等的函数关系。这类定量磨损图谱对于不同陶瓷材料在不同工况下的应用范围尤其具有指导意义。 该院还致力于研究不同工程陶瓷材料配对的摩擦副的边界润滑问题,探讨了许多润滑剂     

人工关节的摩擦学研究、设计和应用

一引言自从摩擦学这门新兴学科于六十年代中期问世以来,迄今已获长足的发展。随着摩擦学研究的广泛发展及其研究成果的广泛应用,各个工业部门包括医学工业部门均已获得巨大的效益。通常认为,摩擦学的研究对象是无生命机体如机械及其零、部件等。其实,有生命的机体同样存在着众多的摩擦学问题。例如牙齿咀嚼是一种摩擦现象;血液在血管中流动也是一     

Applications of ceramics for tribological components

Fine ceramics are expected to be applied as new materials to many tribological components because of their superior heat resistance and corrosion resistance and their high hardness. In this paper, wear and frictional test results from applications of these components in machines are given and the capabilities of fine ceramics are described.     

Tribological behaviour of colloidally processed sialon ceramics sliding against steel under dry conditions

Advanced structural ceramics are presently used in several tribological applications such as precision instrument bearings, water pumps, automotive engine parts and cutting tools inserts. In the present work, the tribological behaviours of colloidally processed and pressureless sintered sialon ceramics with different phases ( and ) have been studied, aiming at increasing the industrial applications of sialon ceramics. The friction and wear behaviour of sialon ceramics against steel DIN-Ck45K were investigated using a pin-on-disk tribometer under dry conditions. Scanning electron microscopy (SEM), and energy dispersion spectroscopy (EDS) were used to analyse the worn surfaces of the sialon ceramics. Under the conditions used, sialon ceramics exhibited a typical mild wear (10^-6 mm³ N^-1 m^-1) and the dominant wear mechanisms present were adhesive and abrasion. The results confirmed that colloidal processing and pressureless sintering are effective methods to prepare wear resistant sialon ceramic components.     

On the Tribological Behaviour of SiC and Alumina Mated Against Different Steels Under Dry Sliding Conditions

There have been several studies regarding the tribological behaviour of ceramics such as SiC and alumina mated against steels or self-mated. Nevertheless, only little is known about possible tribochemical reactions when ceramics are mated against steels. In the present study, ceramic pins made of SiC (EKasicF) or alumina (F99.7) respectively were tested under dry sliding conditions against different steel disc counter bodies using a pin-on-disc tribometer. The different ceramics showed significant differences in their tribological behaviour, i.e., coefficient of friction and wear amount. Especially, the SiC couples showed significant differences in the wear amounts while these were quite similar for the alumina couples. The wear behaviour of the SiC couples is discussed in more detail. A correlation between chromium content of the steel discs was found for the SiC couples. The surfaces of selected specimens were analysed by Auger-Electron-Spectroscopy (AES). Wear for the SiC couples was mainly attributed to tribochemical reactions as far as the steel disc was containing the alloying element chromium in considerable amount. Furthermore, a simple wear schematic is proposed.     

Tribological characterization of alumina and silicon carbide under lubricated sliding

The aim of this study was to investigate the tribological properties of four different advanced ceramics - monolithic alumina, SiC whisker-reinforced alumina, monolithic silicon carbide and SiSiC-during lubricated sliding. Advanced techniques of electron microscopy and spectroscopy have been used to characterize the materials before and after testing. Tests have been performed where two flat discs were rotated against each other under closed contact in an environment of oil and water. The main wear mechanisms of the four ceramics are identified and discussed. What clearly emerges from these studies is the much more reliable performance of the silicon carbides than the aluminas. The silicon carbides have a low wear rate where microfracture and oxidation are the main deteriorating mechanisms. The capability to maintain smooth surfaces and thus also a high degree of hydrodynamic lubrication is largely due to the potential of the water to dissolve formed wear debris. The main wear mechanism of the aluminas is surface fracture. The rough fracture surfaces and the fact that the wear fragments form a discontinuous surface film will reduce the effect of the lubrication, thus accelerating the wear. Furthermore, a deformation layer with microcracks develops in the contact which decreases wear resistance.     

PTFE基复合材料海水润滑下的摩擦学性能研究

研究碳纤维/聚四氟乙烯（CF/PTFE）、玻璃纤维/聚四氟乙烯（GF/PTFE）复合材料与氮化硅陶瓷配副在海水环境下的摩擦学性能与润滑机制,分析滑动速度对摩擦副海水润滑性能的影响规律。结果表明：在海水润滑条件下,随着滑动速度的增加,PTFE、CF/PTFE、GF/PTFE材料与Si3N4陶瓷配副时的摩擦学性能均有明显改善,摩擦因数与磨损率均呈显著降低的趋势,其中CF/PTFE复合材料表现出更为优异的摩擦学性能,在1 000 r/min滑动速度下摩擦因数低至0.026。磨损表面表征结果表明,在海水润滑条件下,PTFE基复合材料在摩擦过程中由于摩擦化学反应生成了润滑膜,可为摩擦副提供良好的润滑和减磨作用,从而减少摩擦磨损行为的发生。     

Tribological properties and processing challenges of bulk structural ceramic nanomaterials

Abstract

With the recognition that bulk nanostructured ceramics, defined by the grain size of at least one of the constituent microstructural phases being smaller than 100 nm, possess some appealing physical, mechanical and tribological properties, they have been the subject of considerable research activities in recent years. Among the various properties of structural ceramics, the most remarkable and reproducible improvement produced by the refinement of the grain size to nanoscale levels or through reinforcement of the matrix by nanosized particles, has been in the tribological properties. This review critically analyses the effects of microstructural refinement to nanoscale levels on the wear resistance of structural ceramics and ceramic composites. This is followed by an overview of the tribological behaviour of different ceramic nanomaterials. It must be noted that although nanostructured ceramics possess superior properties with respect to their conventional counterparts, the challenges involved in the successful processing of such materials have hindered their penetration of the commercial market to any notable degree. In light of this, the review outlines the challenges involved and the techniques developed for the successful processing of bulk nanocrystalline ceramics. Finally, the review concludes with critical comments on some of the unresolved issues related to bulk nanostructured ceramics, along with a brief mention of the scope for future research.     

Lubrication of polyether ether ketone (PEEK) surface by liquid ultrathin films for high wear durability

PEEK, an engineering polymer with many advantages such as lightweight, high thermal stability, high strength coupled with toughness, has often been used as a substitute for metals in applications such as bearings, piston parts, pumps and even biomaterials. However, it shows high coefficient of friction which results in high wear rate when used in tribological applications. This paper seeks to solve tribological problems of high friction and wear for PEEK by applying an ultrathin layer of perfluoropolyether (PFPE) and Multiply-Alkylated Cyclopentane (MAC) lubricants on the surface of PEEK. Results obtained from tribological tests conducted showed that for highly improved tribological performance, there is an optimal initial surface roughness of PEEK surface and lubricant concentration or the thickness of the coatings for both PFPE and MAC lubricant. Also, MAC performs better compared to PFPE for thinner films.     

Effects of a second phase on the tribological properties of Al2O3 and ZrO2 ceramics

The tribological properties of four different materials are investigated, tetragonal zirconia (Y-ZTP), Al₂O₃ dispersed in Y-TZP (ADZ), ZrO₂ dispersed in Al₂O₃ (ZTA) and Al₂O₃ (with 300 ppm MgO). These materials are used as a cylinder sliding against a plate of Y-TZP (TZ-3Y)). Compared to Y-TZP, the wear resistance of ADZ composites is increased by a factor of 4–10. At a contact pressure of 230 MPa, a wear transition for Y-TZP is observed from plastic deformation to microchipping and microfracture due to the high interfacial temperature (450°C–550°C) generated by frictional heating. Because of the higher elastic modulus, hardness and fracture toughness at high temperature, ADZ composites show better wear resistance and a higher transition contact pressure (over 400 MPa) under the present conditions. For Al₂O₃, the transition from mild to severe wear occurs when the contact pressure is changed from 250 to 400 MPa. For ZTA ceramics, the wear behaviour does not change because of the presence of a compressive layer due to the zirconia phase transformation during sliding.

In water the wear resistance for ADZ and ZY5 is almost two orders of magnitude higher than the results under dry conditions. Reduction of the interfacial temperature by using water and the formation of a hydroxide layer at the contact surface by the tribochemical reaction of water with the ceramic, as observed by XPS, gives a positive effect on wear resistance.     

Friction and wear measurements of laser-sintered and coated parts

The aim of this research is the investigation of surface properties, the measurements of friction coefficient and wear rate of laser-sintered and coated parts. The industrial background of this research is to prove applicability of laser-sintered prototype tools for injection moulding of fibre-reinforced polymers, furthermore to increase the wear resistance of unalloyed steel tools by laser coatings. The materials of the test specimens were laser-sintered phosphorous bronze and unalloyed steel. For increase of wear resistance we used hard Co-based and glassy-like Fe-based (FeB) coatings. As counter bodies we used polymers reinforced with short carbon and glass fibres. The laboratory model tests of selective laser-sintered parts were carried out on a pin-on-disk machine. In case of coated parts—with higher wear resistance—we used a cylinder-on-cylinder tribometer. The tribological properties were determined at different load and temperature conditions. The results of the investigation show that the friction coefficient and wear resistance of laser treated surfaces are good. The coefficient of friction of coated specimens is slightly less, but the wear rate is significantly less.