海水环境下材料摩擦学行为研究现状

海洋孕育着地球上的生命,也是人类生存与社会持续发展的基本空间。海洋工程装备是海洋资源开发和海洋经济发展的前提和基础,研究和探讨海洋环境下材料的摩擦行为是发展我国海洋工程装备的重要途径。针对海水环境下材料摩擦学行为的研究现状,重点阐述了陶瓷材料、高分子材料、涂层材料和金属材料在海水环境下的摩擦学性能,旨在为海洋工程装备中摩擦副材料的选择和应用提供参考。     

水润滑轴承用聚合物复合材料的摩擦学研究进展

聚合物复合材料因其优异的自润滑、高化学稳定性和减振降噪等特性而备受关注。以水作为工作介质的水润滑轴承具有环境友好、维护成本低及结构设计简单等特点,已被广泛应用于船舶、水电和化工等领域。首先总结了水润滑轴承用聚合物复合材料特性,归纳了聚合物复合材料在水润滑条件下的摩擦学性能及磨损机制,介绍了提高聚合物复合材料摩擦学性能的常规方法,并进一步探讨了材料内部结构、摩擦界面微观结构与材料宏观摩擦学特性的内在关联。指出促进水润滑聚合物-金属配副摩擦界面原位生长固体润滑特性转移膜,可弥补水膜润滑能力不足、显著提高配副的摩擦学性能,深入研究水润滑状态下复合材料的微观摩擦磨损机制,对于理解水润滑配副的摩擦学机理有重要的意义。     

B_4C陶瓷摩擦学性能研究现状与分析

碳化硼陶瓷以其独特的结构和性能广泛应用于诸多工业领域,其中作为一种耐磨或减磨材料,碳化硼陶瓷的摩擦学性能备受关注。总结了近年来国内外关于碳化硼陶瓷的摩擦学性能的研究报道,并从摩擦温度、负载、湿度、速度、磨程和配副材料等多种影响因素出发,讨论了碳化硼陶瓷的摩擦学特性。从实验结果可以看出,碳化硼陶瓷的摩擦学性能随实验条件的差异而出现较大范围的波动,摩擦因数在0.95～0.02之间。通过分析碳化硼陶瓷的摩擦与减磨机制,分析和讨论了碳化硼的摩擦学性能,并提出了改善其摩擦学性能的方法和建议。     

工程陶瓷-典型金属摩擦副的摩擦学性能及组合优化

以Si3N4,SiC,ZrO2分别与45钢,GCr15,锡青铜QSn4-3,锡基巴氏合金ZChSnSb8-4组成的摩擦副为研究对象,对微量润滑条件下的工程陶瓷-金属摩擦副进行了摩擦磨损正交实验。结果表明:陶瓷-金属摩擦副整体具有良好的摩擦学性能,摩擦因数为0.1~0.25,陶瓷和金属偶件的磨损率均较低,为10-7 mm3/(N·m)数量级。其中,Si3N4-巴氏合金的摩擦因数最低,SiC-巴氏合金的磨损率最小。Si3N4具有自润滑特性,摩擦表面能够形成氧化膜,使其与金属组合具有较佳的摩擦学性能。锡基巴氏合金作为对磨件,易与陶瓷形成金属化合物润滑膜,其摩擦性能优于其他三种金属,Si3N4-锡基巴氏合金组合摩擦学性能最为优异。     

功能性填料改性聚合物材料的摩擦学研究进展

聚合物材料因其质轻、价廉、耐腐蚀以及优异的自润滑特性而广泛应用于工程机械润滑领域中。加入功能性减摩和增强填料复合改性聚合物树脂可以克服本征型高分子材料的一些固有缺陷,得到低摩擦因数、高耐磨性、高承载力以及耐高温等优异特性的摩擦学复合材料。本文综述了功能性填料如碳基材料、过渡金属硫化物、微胶囊、软金属、陶瓷纳米颗粒、矿物盐以及自润滑高分子对复合材料的减摩抗磨效果及机理。同时,力学性能是保证聚合物材料服役性能和使役寿命的关键参数,也会对材料的摩擦学性能带来显著影响。本文还重点论述了纳米颗粒和纤维等填料对复合材料的增强和增韧机理。最后,展望了功能性填料对力学性能与摩擦学性能的协效作用,以及计算机模拟在复合材料摩擦学中应用的发展趋势。     

赛龙材料在海水环境中的吸湿和摩擦学行为

赛龙材料作为一种新型水润滑轴承材料,在海洋工程中有广阔的应用前景,但目前有关海水介质对赛龙材料吸湿性及摩擦学性能的影响研究还不够深入。研究了赛龙材料在海水环境中的吸湿行为和摩擦磨损性能,分析了摩擦工况参数如润滑介质、载荷、转速等对赛龙材料润滑性能的影响规律。结果表明,在各测试条件下,海水均比纯水对赛龙材料有更好的润滑效果,其原因之一为赛龙在海水介质中浸泡后,基体-填料间的结合力更强。     

面向低温环境的聚合物摩擦学性能及其改性研究进展

聚合物及其复合材料具有力学性能好、摩擦系数低、耐磨性能强等优点,常被应用于制造摩擦副关键基础件,如密封圈、齿轮、轴承保持架、转子叶片、活塞等.但迄今针对低温工况的聚合物摩擦学研究甚少,主要工作集中在常温和高温工况.面向低温环境的聚合物及其复合材料的摩擦学应用与相关制备、改性工艺的相关理论并不完备,极端服役环境下聚合物的摩擦学损伤失效机理还尚未完全清楚.此外,聚合物材料虽然具有众多优良的性能,但是其表面硬度低、温度影响大、易变形等缺点也同样明显,限制了其在低温摩擦学领域的应用,为此,研究者通过填充填料、表面处理等方法对聚合物进行了改性研究,取得了一定的成果.目前,由于航空航天等前沿技术的不断发展,聚合物在真空低温环境下的摩擦学性能受到了广泛关注,聚四氟乙烯、聚酰亚胺、聚醚醚酮等聚合物自润滑材料已被应用于空间飞行器领域来制作润滑和密封部件.研究者利用石墨、石墨烯、二硫化钼、芳纶纤维、玻璃纤维等对聚合物进行改性,制备了在低温环境下具有低摩擦系数、高耐磨性的聚醚醚酮/石墨、聚四氟乙烯/芳纶纤维、聚四氟乙烯/超高分子量聚乙烯等复合材料,促进了聚合物在低温摩擦学领域的应用.本文系统分析了低温环境下温度、环境介质、滑动速度、载荷、滑动方向等因素对聚合物摩擦学性能的影响,对面向低温环境的聚合物摩擦学改性进行了简要总结,以期促进聚合物低温环境下摩擦学应用及其相关研究的进一步发展.     

多孔材料的摩擦学性能研究及展望

多孔材料因具有特殊的性能而在某些领域得到深入研究与应用。国内外对多孔材料的摩擦学性能进行了一些研究,但对于多孔材料的摩擦磨损机制还处于探索阶段。着重介绍了陶瓷、金属及聚合物多孔材料摩擦磨损性能的相关研究,指出因材料制备的原因,多孔材料孔隙的均匀性难以得到保障,进而影响多孔材料的自润滑性能;此外对影响多孔材料摩擦磨损性能的其它因素,如多孔材料的孔隙率、孔径及润滑剂种类等方面的研究极为缺乏。最后展望了多孔材料在摩擦学研究上的发展趋势。     

海洋环境下钛及钛合金的腐蚀磨损研究进展

钛和钛合金作为钝化金属合金广泛用于海洋工程领域,具有优异的耐腐蚀性。腐蚀磨损是近年来摩擦学领域的研究热点之一,是影响钝化金属结构材料在腐蚀环境下应用的重要因素之一。围绕腐蚀磨损研究,对近年来国内外关于钛及钛合金在海水环境下的腐蚀磨损行为及机理研究进行了整理综述,并对未来钛合金主要研究发展方向进行了展望。     

中国海洋工程科技2035发展战略研究

提高海洋资源开发能力,发展海洋经济,保护海洋生态环境,坚决维护国家海洋权益,建设海洋强国是我国重要的长期发展战略目标。从全球视野和经略海洋能力来看,我国尚处于探索和开发海洋的初步阶段,需要将海洋资源探查、工程开发利用、环境保护和国家权益维护作为有机整体,开展海洋强国建设的顶层设计。本研究通过一系列海洋跨学科交叉和集成的技术预见分析,研判我国海洋领域的重要技术方向。从海洋环境立体观测技术与装备、海底资源勘查与开发、海洋生物资源勘查与开发、海水和海洋能资源综合利用、海洋环境安全保障及海洋开发装备6个关键领域,提出了面向2035的我国海洋工程科技的愿景、发展重点、发展战略及发展途径。     

Anomalous microstructure and tribological evaluation of AlCrFeNiW0.2Ti0.5 high-entropy alloy coating manufactured by laser cladding in seawater

To evaluate the potential of high entropy alloys for marine applications,a new high entropy alloy coating of AlCrFeNiW0.2Ti0.5 was designed and produced on Q235 steel via laser cladding.The microstructure,microhardness and tribological performances sliding against YG6 cemented carbide,GCr15 steel and Si3N4 ceramic in seawater were studied in detail.The AlCrFeNiW0.2Ti0.5 coating showed an anoma-lous'sunflower-like'morphology and consisted of BCC and ordered B2 phases.The microhardness was approximately 692.5 HV,which was 5 times higher than substrate.The coating showed more excellent tribological performances than Q235 steel and SUS304,a typical material used in seawater environment,sliding against all three coupled balls in seawater.Besides,the wear and friction of AlCrFeNiW0.2Ti0.5 coat-ing sliding against YG6 in seawater were most mild.The main reason was the generation of Mg(OH)2,CaCO3,metal oxides and hydroxides and the formation of protective tribo-film on the worn surface of AlCrFeNiW0.2Ti0.5 coating in the process of reciprocated sliding.This would effectively hinder the direct contact between the worn surfaces of AlCrFeNiW0.2Ti0.5 coating and YG6 ball,resulting in a decrease of friction coefficient and wear rate.Thus the YG6 was an ideal coupled material for AlCrFeNiW0.2Ti0.5 coating in seawater,and the coating would become a promising wear-resisting material in ocean environment.     

Latest progress on tribological properties of industrial materials

Wear is closely related to friction and lubrication; the study of these three subjects is known as tribology. In science and technology it is concerned with interacting surfaces in relative motion. Soft or hard film coating, alloying and composite structuring have all been developed to control wear and friction. This is achieved by improving materials and surfaces with some characteristics that improve resistance to friction and wear. In recent years, several new solid lubricant and modern lubrication concepts have been developed to achieve better lubricity and longer wear life in demanding tribological applications. Most of the traditional solid lubricants were prepared in the form of metal, ceramic and polymer–matrix composites. They have been used successfully in various engineering applications. Recent progress in thin-film deposition technologies has led to the synthesis of new generations of self-lubricating coatings with composite or multilayered architectures, by using multiplex surface treatments. In this study, typical wear behaviors of representative materials of metallic alloys, ceramics, polymeric materials, and composites are reviewed in relation to their friction behaviors. Additionally, modeling for the wear prediction is outlined.     

牙科陶瓷材料的摩擦学性能研究进展

陶瓷材料因其优异的耐磨性、化学稳定性、生物相容性和美观性被广泛用于牙齿缺损和缺失修复。本文首先介绍了牙科陶瓷材料的化学成分、微观结构和力学性能,基于陶瓷材料的磨损与磨蚀机制,归纳总结了牙科陶瓷材料摩擦学性能优化方面所取得的进展,指出陶瓷材料和天然人牙摩擦学性能失配严重制约了陶瓷修复体的临床应用,进而从室验介质、对摩副以及载荷、位移和循环次数等方面分析汇总牙科陶瓷材料摩擦学性能的体外测试方法。最后,从仿生摩擦学角度探讨了牙科陶瓷材料的未来发展趋势,并指出研制仿生陶瓷基复合材料是解决陶瓷修复体与天然人牙摩擦学性能失配难题最具潜力的策略。     

材料表面抗空蚀涂层的研究进展

空蚀现象广泛存在于海洋平台、船舶机械和能源发电等领域。这种腐蚀现象不仅造成了巨大的经济损失,也成为相关从业人员的安全隐患。本文概述了抗空蚀涂层材料技术的研究进展,重点介绍了抗空蚀金属涂层技术和抗空蚀聚合物涂层技术。最后对目前抗空蚀材料存在的问题及未来发展进行了展望。     

Influence of counterface roughness on friction properties of engineering plastics for bearing applications

The study investigates the effects of the roughness of the metal counterface (mirror finished or polished) on the coefficient of dry friction for some of the most common engineering plastics used in current bearing technology. The results show that an optimal roughness for minimum friction is likely to exist for any polymer, and it depends on the bulk properties of the polymer itself. “Soft” plastics characterized by a low modulus of elasticity exhibit better sliding behaviour on very smooth, mirror finished surfaces, whereas for high-modulus plastics lower friction is measured in combination with rougher, polished counterfaces. The influence of the contact pressure and sliding velocity are also investigated and found to depend on the layout of the tribological system.     

Mechanical and tribological properties of self-lubricating metal matrix nanocomposites reinforced by carbon nanotubes (CNTs) and graphene – A review

Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix nanocomposites for structural engineering and functional devices. Carbonous materials, such as graphite, carbon nanotubes (CNT's), and graphene possess unique electrical, mechanical, and thermal properties. Owe to their lubricious nature, these carbonous materials have attracted researchers to synthesize lightweight self-lubricating metal matrix nanocomposites with superior mechanical and tribological properties for several applications in automotive and aerospace industries. This review focuses on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene. The review includes development of self-lubricating nanocomposites, related issues in their processing, their characterization, and investigation of their tribological behavior. The results reveal that adding CNT and graphene to metals decreases both coefficient of friction and wear rate as well as increases the tensile strength. The mechanisms involved for the improved mechanical and tribological behavior is discussed.     

A sensor for measurement of friction coefficient on moving flexible surfaces

Measurement of coefficient of friction between surfaces is of interest in numerous engineering applications. Although laboratory tests of material samples in tribological systems are used to measure the friction coefficient, on-line friction measurement on newly manufactured surfaces, or between two interacting surfaces of interest, is nonexistent. In this paper, we describe a new sensor, called the tribosensor, that accomplishes real-time friction coefficient measurement between materials, where one of the two materials in the tribological pair is being processed or manufactured at high speeds, such as in paper, plastics, aluminum, and other flexible materials. This paper discusses the operating principle of the sensor, design configuration, and performance characterization. Comparison with traditional off-line laboratory measurements is also presented.