纳米过渡金属硫化物在摩擦学应用中的研究进展

介绍了过渡层状金属硫化物MX2（M=Mo、W；X=S、Se）的结构和独特的性质，综述了无机类富勒烯过渡金属硫化物纳米材料的摩擦学研究现状和近年来的研究成果。通过对包括纳米颗粒、纳米薄膜在内的纳米硫化物摩擦性能研究的介绍，评述了纳米金属硫化物的抗磨减摩机制，如滚动滑动摩擦机制、化学反应、第三体等，并对纳米摩擦学的表征方法和研究手段进行了总结。最后展望了纳米过渡层状金属硫化物在摩擦学应用中存在的问题及发展趋势。     

纳米表面工程与摩擦学

利用表面工程技术解决摩擦磨损问题具有高效、实用等特点。随着科学技术的迅速发展，纳米材料和纳米技术在表面工程中得到了广泛应用，由此出现了“纳米表面工程”。利用纳米表面工程技术制备的涂层和镀层有着非常优异的摩擦学性能。本文叙述了作者近年来的有关工作，包括热喷涂纳米陶瓷涂层、热喷涂纳米自润滑涂层、纳米陶瓷／聚合物复合涂层、纳米复合电镀层以及纳米电泳沉积层的摩擦磨损特性和机制。     

纳米材料作为润滑添加剂的研究回顾及目前的发展动向与展望

回顾了纳米材料作为润滑添加剂的研究状况。比较了不同纳米材料添加剂对摩擦学性能的影响；综述了纳米材料的抗磨减摩机理。介绍当今国外此领域的研究现状，指出结构型纳米材料是在本领域的研究新热点。并展望了纳米材料作为润滑油添加剂的发展方向。     

纳米粒子作润滑油添加剂的研究与展望

纳米粒子作润滑油添加剂表现出极好的摩擦学性能。本文综述了各种类型纳米闰子作润滑油添加剂的摩擦学性能和机理，总结了纳米粒子作润滑油添加剂的特点，并提出了需要进一步研究的方向。     

纳米铜添加工艺对润滑油摩擦学性能的影响

探讨了纳米铜不同分散工艺和添加量对润滑油摩擦学性能的影响。分别采用超声分散和球磨分散工艺，将3种不同工艺制备的纳米铜材料溶于SF15W／40机油中，在T-11摩擦磨损试验机上进行摩擦学性能试验。结果表明，其中一种纳米铜能够提高基础油的减摩性能，采用超声分散比采用球磨分散的减摩性能好。随着纳米铜浓度的增加抗磨性能有明显的提高，分析认为纳米铜在摩擦表面的沉积有利于提高摩擦学性能。     

环保型纳米润滑材料的研究

从环保角度,选择了两种纳米材料作为润滑油抗磨、极压添加剂。介绍了纳米材料的制备,根据亲水亲油平衡值(HLB)选择了合适的表面活性剂,并将其加入到含有单种或两种复合纳米粒子的润滑油中进行表面改性,采用四球摩擦磨损试验机测定含纳米粒子的润滑油的摩擦学性能。结果表明:含纳米粒子的润滑油具有良好的抗磨减摩性能,且含复合纳米粒子的润滑材料的抗磨减摩性能比单种纳米粒子的润滑材料的抗磨减摩性能好。这里还探讨了纳米润滑材料的抗磨减摩机理。     

油润滑纳米添加剂摩擦学设计及研究中几个值得商榷的问题

从材料学、化学、摩擦学、表面工程角度分析阐述了纳米润滑油添加剂组分选择、分散稳定修饰剂设计、摩擦学性能评价和机理研究方面存在的几个问题和认识上的一些误区．指出在作油润滑纳米润滑材料的摩擦学设计时，所选择的纳米材料应对酸、氧特别是热氧和纳米修饰剂表现出惰性；对普通摩擦副来说，纳米粒子的“分子轴承”作用机制其作用微乎其微的。当摩擦副相互接近程度达到介观或微观尺度时．纳米微球的“分子轴承”作用才明显，产生润滑甚至超润滑；对普通摩擦副而言，纳米粒子在短时间内的机械抛光作用并不会太明显，而长期抛光作用则取决于摩擦过程中纳米粒子机械抛光作用和机械摩擦磨损作用两者之间的竞争。     

纳米颗粒增强铜基摩擦材料的摩擦学性能

基于粉末冶金法分别制备了纳米氮化铝和纳米石墨增强铜基摩擦材料,研究了纳米颗粒对铜基摩擦材料的摩擦磨损和耐热性能的影响规律.采用扫描电子显微镜(SEM)分析了材料的微观结构和磨损形貌,并利用惯性摩擦磨损试验机考核其摩擦学性能.实验结果表明:与未添加纳米颗粒的摩擦材料相比,添加纳米氮化铝和纳米石墨的摩擦材料的摩擦因数高而稳定,且随接合次数增加无明显衰退现象;耐磨性能分别提高了25％和11％;耐热性能分别提高了18％和25％.未添加纳米颗粒的摩擦材料的磨损机制主要为犁沟式磨料磨损,纳米氮化铝和纳米石墨能减少摩擦材料的磨料磨损,从而增强了摩擦材料的耐磨性.实验结果显示,纳米氮化铝和纳米石墨可显著提高铜基摩擦材料的摩擦学性能.     

纳米连接过程的分子动力学模拟研究进展

纳米材料因其特有的结构和性能而得到广泛的应用，纳米连接技术也随之发展起来。在纳米加工领域，虽然有很多先进的显微分析手段，但由于实时观察技术的限制，材料的很多现象和行为很难通过实验进行观测和分析，而分子动力学适用于几纳米到几十纳米的三维空间尺度和纳秒以下的时间尺度，同纳米加工领域很多过程的时间尺度和空间尺度保持一致，因此，利用分子动力学模拟纳米材料性能和连接过程原子的动力学行为是可行的。综述了纳米材料（包括纳米多层膜、纳米线、碳纳米管、纳米颗粒）在纳米连接过程以及连接大尺寸材料过程中的分子动力学模拟研究进展，模拟结果与实验结果基本吻合。结合最新研究进展，讨论了分子动力学模拟在纳米连接应用中的存在问题、解决办法和发展趋势。     

纳米CaCO3、Cu混合物润滑油添加剂的摩擦学性能

采用纳米碳酸钙、纳米铜粒子混合物作为润滑油添加剂，利用四球摩擦磨损试验机考察了含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能；用扫描电子显微镜（SEM）考察了磨痕表面的形貌；用原子力显微镜和扫描电子显微镜（SEM）观察分析了在磨损表面纳米粒子的形态与分布。研究结果表明，纳米碳酸钙、纳米铜的混合粒子的总添加量为0.6％，质量比为1：1时，润滑油具有最佳的摩擦学性能；润滑油中纳米碳酸钙、纳米铜混合物粒子添加剂的优良摩擦学性能与纳米粒子在表面存在形态相关。     

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。     

类金刚石薄膜水润滑摩擦学特性研究进展

综述类金刚石薄膜水润滑摩擦学特性的研究进展,评述薄膜在水环境中的摩擦磨损特性,分析薄膜种类、元素掺杂、对摩材料以及微结构对DLC薄膜水润滑摩擦学特性的影响,并阐述DLC薄膜在水中的摩擦磨损机制。指出:DLC薄膜水润滑摩擦学特性受薄膜制备参数和摩擦试验环境影响,通过与微结构的耦合可以进一步改善类金刚石薄膜的摩擦学特性。同时还展望了类金刚石薄膜水润滑摩擦学未来研究方向。     

辐照对高分子材料基本性能及摩擦学特性影响的研究进展

随着空间高科技的发展,对高分子材料不断地提出更高的要求,除要求其具有良好的物理和力学性能外,还要求具有耐辐照性能。在总结了照对高分子材料基本性能及摩擦学牡性的影响的研究的同时,介绍了辐照分子材料摩磨损机理方面的初步结果。针对辐照高分子材料摩擦学研究现状,为深入研究辐照后高分子材料摩擦磨损性能变化的规律及高分子材料在辐照环境下的应用提供理论依据是很有意义的工作。     

Wear behaviour of medical engineering materials

Assessing the tribological properties of medical engineering materials is an extremely complex problem which can be conclusively resolved only after many years' service of the implanted material in the human body. The risk for the patient can be greatly reduced by service simulation tests and by supplementary biological compatibility studies. By elaborate test methods that yield reproducible tribological data within tolerable test periods, favourable conditions have been created for the systematic further development of surgical implant materials and prosthesis designs. Some new materials (e.g. ceramic and fibre-reinforced materials) appear to be very promising, so that substantial improvements may be expected in the future. Simplified test methods designed to characterize the frictional and wear properties of materials are important for the preselection of materials and material combinations and contribute significantly to the exploration of the fundamental tribological mechanisms. These tests cannot however provide quantitative data on the life expectancy of joint replacements as demanded by surgeons, because the tribological properties of surgical implant materials cannot be evaluated independently of the design and manufacture of the prosthetic devices.     

碳纳米管/丁腈橡胶复合材料力学及摩擦性能的分子动力学模拟*

采用分子动力学模拟技术,从分子水平研究碳纳米管(CNTs)增强丁腈橡胶(NBR)复合材料的力学性能及摩擦学性能。运用恒应变法计算材料的力学性能,分别建立纯NBR和CNTs/NBR复合材料的3层模型,并对顶层和底层的铁摩擦副施加剪切载荷,研究材料的摩擦学性能。研究结果表明：在摩擦过程中,由于CNTs表面存在很强的吸附力,抑制了NBR分子链的迁移率,使得CNTs和聚合物分子链间的相互作用增强;CNTs/NBR复合材料具有更高的致密性以及更强的结构,从而表现出了比纯NBR更加优异的力学和摩擦学性能。     

The surface layer of friction plastics

The tribological problems of plastics used for friction brakes with particular emphasis on the design problems of materials with optimal characteristics for the working conditions of shoe brakes for underground railways were investigated. The phenomena associated with the friction and wear of these materials were identified by examining the surface layers of samples using the following techniques: optical and scanning electron microscopy, X-ray microanalysis and thermogravimetric analysis at temperatures up to 1270 K. A model of the structure of the surface layer of friction materials was developed. It consists of five layers which differ in composition, structure and properties. This model is important in the development of new friction materials with specified tribological characteristics.     

铝-铅固体自润滑材料

用常规的粉末冶金方法成功地制备出铝铅固体自润滑材料，并对其力学性能和摩擦磨损性能进行了研究。实验结果显示，铅的加入对材料的磨擦学性能有着较大的影响。对其中的摩擦机理也作了初步探讨。     

The Microstructure and Wear Characteristics of Cu–Fe Matrix Friction Material with Addition of SiC

The Cu–Fe matrix continuous braking friction materials using SiC as abrasive were fabricated by powder metallurgy technique, and the effect of content and size of SiC were investigated. The tribological properties of friction materials sliding against AISI 1045 steel ring were carried out on a block-on-ring tester at different loads and sliding speeds. The strengthening effect of nano-SiC (55 nm) was superior to that of micro-SiC (70 μm) of the tribological properties for friction materials. The friction coefficients of friction materials increased with increasing nano-SiC content. However, the wear rates decreased with increasing nano-SiC content and then increased when the content of nano-SiC particle exceeded 10 wt%. The specimen contained 10% nano-SiC had the best tribological properties at different testing conditions.     

Multi-phase materials and their surface contact behaviour with reference to friction and wear

The recent advances in the development of composite surface coatings and the increasing tribological application of multi-phase materials in engineering require a more rigorous treatment of the problem of the contact of surfaces of such materials. This paper considers the surface contact behaviour of materials having contrasting physical properties and the results presented quantitatively identify the boundaries of three contact regimes, purely elastic, elastic/plastic and predominantly plastic. The treatment also offers a method for determining the real areas of contact and corresponding supported loads associated with the modes of deformation of each phase. This is particularly important for predicting the friction and wear characteristics of multi-phase materials.     

Tribological surfaces of organic brake pads

Despite the enormous amount of testing and development of automotive brakes and brake pad materials, rather little is known about their tribological contact situation on a microscopic level. The sliding of an organic brake pad against a grey cast iron rotor is very different from most tribological systems. When worn against the rotor, the complex structure and very inhomogeneous composition of the pads results in a particular surface structure, with large contact plateaus rising a few micrometers above the rest of the surface [Wear 232 (1999) 163; Wear 2000 (submitted for publication); Proceedings of the Nordtrib 2000, vol. 2 (2000), 358]. The present investigation involves a more comprehensive study of the formation, mechanical properties and composition of the tribological surfaces of such pads, using high resolution scanning electron microscopy, nanoindentation, energy dispersive X-ray analysis and three-dimensional profilometry using white light optical interferometry. The observations are discussed and correlated to observed friction phenomena.