钛合金表面自润滑耐磨复合材料涂层研究进展

自润滑耐磨复合材料涂层有良好的减磨耐磨性能,在材料的表面改性研究领域中发挥着巨大作用。为了使钛合金在使用寿命上能够获得较大程度的提升,利用激光熔覆技术向钛合金基材表面加入一定固体润滑剂和增强相颗粒,制备出的钛合金自润滑耐磨涂层可以显著提高涂层的耐磨性能以及减摩性能。基于国内外研究钛合金复合材料涂层的研究现状,阐述了钛合金表面耐磨复合材料涂层和自润滑涂层的耐磨损强化机理,讨论了自润滑涂层和耐磨涂层的材料选取方式。结果表明,新型固体润滑剂不仅可以降低材料表面的摩擦系数,而且因自身的化学惰性、适应能力强以及对环境污染小等特点,避免了传统润滑剂(润滑油、润滑脂)存在的缺陷;金属基陶瓷复合材料的综合性能更加显著,弥补了单一硬质相颗粒的不足,可作为耐磨涂层的重要组分。最后展望了该涂层未来的发展前景。     

高温固体自润滑涂层的发展

在最近几十年中，高温固体润滑剂得到了高速的发展和广泛的工业应用，特别是在机械加工行业中得到了体现。本文在综合国内外研究和报道的基础上，归纳了高温固体润滑剂的类别划分，阐述了高温固体自润滑涂层和制备工艺的发展，提出了高温固体自润滑涂层设计的概念，指出了高温固体自润滑涂层发展趋势。     

熔渗型宽温域复合固体润滑剂设计及其摩擦学性能研究

设计一种可用于300~800℃宽温度范围润滑的熔渗型Pb-Sn-Ag-RE复合固体润滑剂。基于润湿试验研究不同组分与配比对其润湿性能的影响;采用高频感应熔渗工艺,制备出熔渗型高温自润滑复合材料;利用XP-5型高温摩擦磨损试验机考察其摩擦磨损性能,运用扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析磨损表面形貌、成分及结构。结果表明:不同组分组成对基体的润湿性有很大的影响,在Pb-Sn系固体润滑剂中添加Ag、RE既能提高其对母材的润湿性能,又能改善自润滑材料的摩擦磨损性能;熔渗Pb-Sn-Ag-RE复合固体润滑剂制备的复合材料具有良好的高温自润滑性能,其600℃下的平均摩擦因数约为0.28。     

减摩耐磨激光熔覆涂层的研究现状及发展趋势

激光熔覆是一种新型的表面改性技术,对于提高材料表面的耐磨性具有重要意义。阐述采用激光熔覆技术来提高基体材料表面减摩耐磨性能方面的研究进展。首先介绍激光熔覆技术制备的Fe、Ni、Co基自熔性合金涂层及组织结构特征,指出这些涂层存在气孔、裂纹和成分偏析与组织不均匀性等缺陷。然后指出通过合理的粉末材料的选择及配比以及合理优化的熔覆工艺参数,可改善涂层性能,制备出表面性能优异的金属陶瓷复合涂层/稀土添加复合层;同时指明相比单一外部能量场,复合外部能场辅助激光熔覆制备的涂层显现出更优异的减摩耐磨效果。最后阐述新型耐磨涂层材料(自润滑耐磨涂层、高熵合金耐磨涂层,梯度耐磨涂层和纳米耐磨涂层)的组织结构和性能特征,指出高性能新型耐磨涂层可适用于多元场景,是未来研究的重点方向,并总结与展望激光熔覆制备耐磨涂层研究的发展趋势与应用方向。     

浸渗型高温自润滑金属陶瓷复合材料的制备及其性能

采用熔融铅-锡-银-稀土系固体润滑剂与TiC/FeWCrMoV微孔金属陶瓷预制体真空压力熔渗复合法制备浸渗型高温自润滑复合材料,研究了制备工艺参数对该复合材料熔渗质量及其性能的影响,以确定其最佳工艺,并在高温摩擦磨损试验机上考察了其摩擦磨损性能;用扫描电子显微镜和光电子能谱仪分析了材料的显微组织及其磨损表面的形貌。结果表明:其最佳烧结工艺为1230℃烧结保温60min,最佳熔渗工艺为750℃、5MPa压力下熔渗60min;可得到由金属陶瓷硬质相与多元润滑剂软质相组成的互穿网络结构高温自润滑复合材料,当润滑剂体积分数超过一定量时(13%)该材料既具有高的强韧性和耐磨性,又具有良好的高温摩擦学性能。     

原苏联有关摩擦学研究单位情况介绍

一、诺沃切尔卡斯克“Орион”设计与工艺专业研究所该所主要从事减摩耐磨保护涂层、减摩自润滑材料、“无磨损效应”润滑脂等方面的研究。现将该所减摩耐磨保护涂层介绍如下,有关减摩自润滑材料的情况已在本刊1992年第4期第61～65页上介绍过,在此不再赘述。     

Ti-Al合金高温自润滑材料抗摩擦磨损模型

采用真空热压成形工艺,通过添加不同体积分数的复合润滑剂,制备出了48Ti-48Al-2Nb-2Cr自润滑材料。建立了其高温抗摩擦磨损模型,考察了其磨损率影响因素,并通过高温磨损试验分析了其减摩机理。结果表明：添加固体润滑剂对自润滑材料的磨损率有很大影响,其中,当添加的复合润滑剂（38％CaF2—62％BaF2）的体积分数为109／6时自润滑材料的磨损率最低;自润滑材料在摩擦磨损过程中,能够在磨损表面形成一层较完整的固体润滑膜,膜的存在使得自润滑材料具有很好的减摩能力。模型的建立及成膜机理的分析为Ti—Al系合金高温环境下的使用提供了理论依据。     

原位反应自润滑陶瓷刀具的设计开发及其减摩机理研究

本文提出了原位反应自润滑陶瓷刀具的概念,即利用刀具切削高温作用下的摩擦化学反应,在刀具材料表面原位生成具有润滑作用的反应膜,从而实现刀具的自润滑。研制成功以Al2O3为基体、ZrB2为增强相、ZrO2为弥散相的新型自润滑陶瓷刀具材料,并对其制备工艺、性能、微观结构等进行了深入的研究。对原位反应自润滑刀具材料的高温氧化和摩擦磨损特性     

宽温域矿用合金制备及其摩擦磨损性能研究

为改善矿用内燃机零部件在宽温域范围内的摩擦学性能,采用热压烧结技术制备了不同比例固体润滑剂(7％MoS2+7％ZnO,9％MoS2+5％ZnO,11％MoS2+3％ZnO)的钴基复合材料,通过高温摩擦磨损试验机测试了材料在室温、200℃、400℃、600℃和800℃的摩擦学性能,研究了材料的微观结构、物相组成和磨损机理...     

Sn-Ag-Cu系高温自润滑材料的摩擦学特性

采用真空压力浸渗复合技术将熔融固体润滑剂熔渗到微孔金属陶瓷基体中,制备熔渗型Sn-Ag-Cu系高温自润滑复合材料;利用XP-2型高温摩擦磨损销盘型试验机考察其高温摩擦磨损性能,采用SEM和XRD分析其磨损表面形貌、成分,探讨其高温自润滑机制。研究结果表明:制备的自润滑复合材料在600℃高温下具有较低的摩擦因数和磨损率,这是因为在高温摩擦磨损过程中熔渗于基体材料中的固体润滑剂在高温、摩擦热和应力的作用下从微孔中析出,并在摩擦界面形成由Cu_3Sn、Cu_αSb_γ、Fe_3Sn、Ag_3Sn等金属间化合物组成的润滑膜。该润滑膜使材料具有良好高温自润滑性能,其中的Ag元素对摩擦因数的影响较大。     

激光熔覆陶瓷涂层研究现状与展望

陶瓷材料具有高硬度、高熔点、高耐蚀等特性,常被应用于机械装备关键零部件的表面强化改性和再制造修复。随着装备服役工况日益苛刻,传统金属材料所制备的装备运动部件在服役过程中易于发生磨损、腐蚀、变形等失效,进而导致服役性能退化,严重时甚至引发装备恶性故障。激光熔覆作为一种高效的表面强化和再制造技术,在提升基材表面耐磨、耐蚀、耐热、抗高温氧化等性能方面具有重要应用前景。通过激光熔覆技术在零部件表面制备陶瓷涂层,对于延长关键零部件寿命、提高资源利用率、节约稀贵金属材料具有重要意义。首先按照陶瓷涂层的组织结构和成形机理对激光熔覆陶瓷涂层进行了分类介绍;然后结合激光熔覆制备陶瓷涂层的典型缺陷详细阐述了涂层质量优化的常用方法;而后综述了激光熔覆陶瓷涂层在提升零件耐腐蚀、耐磨损、耐高温性能和提高生物相容性等方面的应用情况;最后,总结了激光熔覆陶瓷涂层技术发展现状,并展望了激光熔覆陶瓷涂层技术的发展趋势。     

Wear and Friction of TiAl Matrix Self-Lubricating Composites against Si3N4 in Air at Room and Elevated Temperatures

More durable, low-friction bearing materials over a wide temperature range are needed for turbine components and other high-temperature bearing applications. The current study reported the tribological properties of TiAl matrix self-lubricating composites (TMC) containing MoS₂ (a low-temperature lubricant, below 500°C), hBN (a medium-temperature lubricant, below 600°C), and Ti₃SiC₂ (a high-temperature lubricant, above 600°C) designated as MhT against an Si₃N₄ counterface at temperatures ranging from 25 to 800°C in air. The load was 10 N and the sliding speed was 0.2 m/s for all tests. Tribological studies indicated that TMC containing MhT showed a lower friction coefficient and wear rate in comparison to TiAl-based alloy at all test temperatures, which was attributed to the excellent synergetic lubricating effect of MoS₂, hBN, and Ti₃SiC₂. TMC containing 5 wt% MhT exhibited the best tribological properties over a wide temperature range.     

汽车零部件铝合金轴瓦及其表面涂层的产品解析

轴承部件具有耐磨、耐蚀、一定温度区间的热化学稳定性以及优良的润滑特性。某进口铝合金轴瓦经过表面涂层处理后,具有良好的无油自润滑性能。借助电子探针显微分析仪器EPMA、能量色散X射线荧光光谱仪EDX、X射线光电子能谱仪XPS和傅立叶变换红外光谱仪FTIR,分析其基体和涂层信息,推断了其实现方案,为开发类似的产品工艺分析方案提供了一定的参考。     

Tribological Properties of TiAl Matrix Self-Lubricating Composites Containing Multilayer Graphene and Ti3SiC2 at High Temperatures

An investigation is conducted on the unexplored synergistic effects of multilayer graphene (MLG) and Ti₃SiC₂ in self-lubricating composites for use in high-temperature friction and wear applications. The tribological properties of TiAl matrix self-lubricating composites with different solid lubricant additions (Ti₃SiC₂-MLG, MLG) are investigated from room temperature to 800°C using a rotating ball-on-disk configuration. Tribological results suggest the evolution of lubrication properties of MLG and the excellent synergistic lubricating effect of MLG and Ti₃SiC₂ as the testing temperature changes. It can be deduced that MLG has great potential applications as a promising high-temperature solid lubricant within 400°C, and a combination of MLG and Ti₃SiC₂ is an effective way to achieve and maintain desired tribological properties over a wide temperature range.     

Low temperature investigations on frictional behaviour and wear resistance of solid lubricant coatings

The tribological characteristics of polymer-based solid lubricant coatings under frictional stressing in vacuum at 293, 120 or 77 K were studied. Vacuum-friction apparatus with cryogenic pumps and low-temperature tribometer designed at SR&DB of ILTP&E was used for sliding tests. It was found that the coefficient of friction is somewhat higher at low than at room temperatures. The effect of temperature decrease on the wear life of solid lubricant coatings is ambiguous and determined by the direction of changes in physical and mechanical characteristics of a solid lubricant coating under cooling and by the rate of the process of a binder tribodestruction.     

A Nickel-Alloy-Based High-Temperature Self-Lubricating Composite with Simultaneously Superior Lubricity and High Strength

It is a challenge to design self-lubricating materials that exhibit and maintain reduced friction coefficient as well as high strength over a wide range of temperatures. A high-temperature self-lubricating nickel-alloy-based composite was created using the hot pressing technique. The composite exhibited high relative density, and simultaneously superior lubricating properties, average friction coefficient below 0.25 from room temperature to 800 °C, and high strength, 470 MPa of tensile strength and 1500 MPa of compressive strength. The composite was very promising in high-temperature tribology.     

边界润滑摩擦面固体润滑涂层技术发展的若干趋势

随着表面工程与涂层技术的发展,固体润滑涂层在机械零件上得到了广泛的应用,涂层材料与涂层工艺取得了很大的进展。本文论述了边界润滑摩擦面固体润滑涂层技术发展的若干趋势,指出开发新的涂层材料、涂层结构、涂层工艺,实现固/液混合润滑,以及利用涂层激光纹理技术提高润滑效果是固体润滑涂层技术发展的重要方向。     

Wear-resistant hard titanium carbide coatings for space applications

Hard, wear-resistant and self-lubricating titanium carbide coatings produced by chemical vapour deposition are used to improve the tribological properties of high precision components for mechanisms that must operate in extreme environments.The two main space tribology areas, where such coatings have made a breakthrough, are ball bearings and fretting joints. This paper presents a brief historical background of the technology, the main coating properties and some areas of application.     

Investigation on MoS2 and graphite coatings and their effects on the tribological properties of the radial spherical plain bearings

With constant enlargement of the application areas of the spherical plain bearings, higher quality lubrication of the bearings is required. To solve the lubricating problems of spherical plain bearings under high temperature, high vacuum, high speed, heavy loads and strong oxidation conditions, it is urgent for us to develop more excellent self-lubricating technologies. In this paper, the bonded solid lubricant coatings, which use inorganic phosphate as the binder, the mixture of MoS2 and graphite with two different weight proportions as the solid lubricant, are prepared by spraying under three different spray gun pressures. The bonding strength tests on the coatings show that the best spraying pressure is 0.2 MPa and the better mixing proportion of MoS2 to Graphite is 3:1. Then for the radial spherical plain bearings with steel/steel friction pair, after the coatings are made on the inner ring outer surfaces, the friction coefficient, the wear loss and the friction temperature of the bearings under four oscillating frequencies are investigated by a self-made tribo-tester. The test results, SEM of the worn morphologies and EDS of worn areas show that tribological properties of the bearing are obviously improved by the bonded solid lubricant coatings. When sprayed under the spray gun pressure of 0.2 MPa, the bearings have better anti-friction and anti-wear properties than those sprayed under 0.1 MPa and 0.3 MPa. Further as proved from the XPS analysis, between the coating with 3:1 mixing ratio of MoS2 to Graphite and the coating with 1:1 ratio, the former has less oxidation occurred on the surface and therefore has better tribological characteristics than the latter. This paper provides a reference to developing a new product of the radial spherical plain bearings with high bonding strength, oxidation resistance and abrasion resistance.     

高温自润滑材料孔隙弯曲角度对润滑剂输出的影响

应用有限元分析方法,研究在高温工作环境下,烧结自润滑材料中孔隙弯曲对润滑剂输出的影响。基于建立的高温自润滑多孔材料结构分析模型,分析不同孔隙折角角度和折孔结构在摩擦热的作用下,孔隙中润滑剂输出特性。结果表明:在理想的孔隙模型中,贯穿摩擦面表层的孔隙为直孔段,且直孔段高度大于模型整体的1/4时,有利于润滑剂输出;与贯穿摩擦面表层直孔相连的折孔,可储存较多的润滑剂,并可向直孔中进行补偿,延长材料的使用寿命。