环氧基耐热耐磨自润滑涂料的制备及性能研究

以环氧树脂TGDDM和固化剂A及固化剂B为基体,添加聚四氟乙烯(PTFE)、石墨和碳纤维作为固体润滑剂,制备了一种环氧基耐热耐磨自润滑涂料。涂料在150℃×1h的条件下固化,研究了3种填料对涂膜性能的影响。结果表明,石墨能有效降低涂膜的摩擦因数和磨损量,但会降低涂膜的力学性能;过多的PTFE对涂膜的摩擦因数影响不大,但会急剧降低涂膜的耐磨性和力学性能;碳纤维使涂膜的摩擦因数增大,但对降低涂膜的磨损量和提高力学性能却十分有效。石墨、PTFE和碳纤维的最佳用量分别为20份、40份和30份。     

氟化石墨的制备及表征

通过石墨与电解熔盐ＫＦ·２ＨＦ的产生的氟气反应,制得了氟化石墨。采用扫描电镜,Ｘ射线衍射和红外光谱对其形貌和结构进行测定,并研究了反应温度对氟化石墨结构的影响,初步探讨了氟化石墨的反应机理。     

Cr——氟化石墨复合镀层在高温轴承中的应用研究

本文对热轧钢运输链上的轴承进行失效分析，找出了主要失效的原因。采用自润滑Ｃｒ－氟化石墨复合镀层代替轴承中的脂润滑。利用电沉积工艺制备了Ｃｒ－氟化石墨镀层，并在摩擦磨损试验机上对镀层进行摩擦系数和耐磨性的试验研究，认为润滑剂存在时，镀层中氟化石墨的含量不影响摩擦系数。在干摩擦时，镀层中氟化石墨的含量增加，摩擦系数随这降低。镀层的耐磨性主要取决于镀层的硬度。     

纳米级氟化石墨作为润滑剂添加剂的摩擦学性能研究

探讨了纳米级氟化石墨的结构特征和润滑原理,使用四球摩擦试验机研究了纳米级氟化石墨的摩擦学性能。研究表明,纳米级氟化石墨对钢-钢摩擦副表现出良好的抗磨减摩性能,与未加添加剂的基础油相比,可使磨斑直径平均减少25%以上,摩擦因数降低35%左右;具有较好的承载能力,使用效果稍好于T321;与T301配伍后具有增效性,与其它添加剂配伍后具有明显的减摩作用。     

氟化石墨在润滑方面的应用研究

氟化石墨作为石墨的改性材料,润滑性能优良。文中详细介绍了氟化石墨在作为固体润滑剂,润滑涂料方面的应用。     

氟化石墨/氟碳复合涂层耐磨防腐性能研究

以氟化石墨（FGi）填充改性氟碳（FEVE）涂料,制备氟化石墨/氟碳（FGi/FEVE）复合涂层,并对其附着力、硬度以及耐磨防腐性能等进行分析,探讨其耐磨防腐作用机制。结果表明：FGi中C-F键的存在,不仅增加了涂层与填料之间的界面相容性,进一步增强复合涂层的热稳定性,提升附着强度与硬度,同时具有优异的疏水性能,使涂层表面接触角由84.5°提升至102.0°。电化学测试表明,质量分数1%FGi改性FEVE复合涂层的低频阻抗模量为3.1×10⁵Ω·cm²,与纯FEVE涂层相比,提升了近1个数量级,表明复合涂层具有更好的防腐性能。这归因于FGi与固化剂N75之间形成的氢键,增加了FGi在FEVE涂层中的分散性,能更有效阻止腐蚀介质的渗透。摩擦测试表明：质量分数1%的FGi可以使FGi/FEVE复合涂层的摩擦因数降低16.9%、磨损率降低48.0%。FGi填充改性增强了FEVE涂层的电绝缘性和疏水性,同时发挥物理屏障作用,能有效防止基底受到腐蚀并阻止裂纹扩展,从而有效提升了FGi/FEVE复合涂层的耐磨防腐性能。     

我厂应用国产耐磨涂层材料的情况

国内研制和推广应用耐磨涂层材料始于1975年,至今已有广州机床研究所的HNT型、FT型和JKC型耐磨涂层材料,北京第一机床厂铣床研究所的含氟耐磨涂层材料。 HNT型耐磨涂料是以液体环氧树脂为基体,通过一定的混合工艺,把其它各种填料和性能改进剂混入其中组成;FT型涂料是在HNT型涂料的基础上进一步研制成的高性能涂料。这两种涂料已广泛应用于各类大型机床的制造和修理。 含氟耐磨涂层涂料也以环氧树脂为基体,加进一定数量的聚四氟乙烯(作为固体润滑剂)以及抗磨剂、增塑剂等组成。这种涂料应用在机床工作台导轨、轴瓦、传动蜗母条,以及车床的溜板、尾座、尾座孔等部位的维修上。 JKC型耐磨涂层材料是以不饱和聚酯为基体的新型涂层材料,在其研制和应用的总结报告中写道:“70年代中、后期,国内外只开展对环氧基型耐磨涂层材料的研究和应用。以不饱和聚酯基型耐磨涂层材料的研究至今尚未见有报道。实际上,不饱和聚酯有它独特的优点,从经济角度看,其原材料来源充裕、广泛,成本低廉(约为环氧树脂的40～50％);从工艺角度看,可人为地控制它的使用期(胶凝时间),又可将它制成呈触变状的糊状物,涂敷在倾斜、垂直或倒置的复杂形面上不会产生流胶现象,给施工操作带来极大方便,     

超细化石墨在植物油中的摩擦学性能考察

通过四球机考查了超细氟化石墨在植物油（菜籽油、蓖麻油、大豆油）中的摩擦学特性，并与极压抗磨剂氯化石蜡（Ｔ３０２）、硫化异丁烯（Ｔ３２１）和ＺＤＴＰ（Ｔ２０２）相比较，结果表明：超细氟化石墨在植物油中具有优良的润滑性能，其摩擦性能明显优于Ｔ３２１和Ｔ３０２，其抗磨性比ＺＤＴＰ稍差，但含２％超细氟化石墨的矿油的抗磨性和承载能力相当或优于植物油。     

MoS_2对PTFE基粘结固体润滑涂层摩擦学和附着性能的影响

以聚四氟乙烯(PTFE)作为固体润滑剂,以MoS2粉作为填料,配制了PTFE和MoS2粉质量比分别为1…2,3…2和5…2的三种涂料(环氧树酯作为粘结剂),利用压缩空气喷涂法在GCr15钢基体上进行喷涂,然后分别在80,120,160℃固化制得了PTFE基粘结固体润滑涂层,研究了MoS2对涂层摩擦学性能和附着性能的影响。结果表明:涂料中PTFE和MoS2的质量比为5…2时,填料与固体润滑剂的协同达到最优,且当固化温度为120℃时,该配方涂层的摩擦学性能和附着性能最优,摩擦因数为0.125,磨损量约为0.008 3mm3,附着力为16.73N。     

几种纳米添加剂在环境友好润滑剂中的摩擦化学特性

采用机械化学修饰法研制了三种纳米润滑添加剂,二硫化钼(MoS2)、聚四氟乙烯(PTFE)和氟化石墨(CxFy),考察了这些纳米级润滑剂在环境友好润滑剂中的摩擦化学特性。结果发现：这些纳米添加剂在环境友好润滑剂中具有较好的抗磨性能和良好的减摩性能;减摩性能优于常用的极压抗磨剂,其机理是在摩擦副表面形成迁移膜,起“滚动微轴承”的作用。     

Microstructural Characterization of Wear Particles Formed During Tribological Stressing of TiC and Ti(C,N) Coatings

An attempt was undertaken to obtain a better understanding of the tribological properties of two wear-resistant coatings on tool steel by structural and microchemical analysis of wear particles using a transmission electron microscope. Coatings were deposited by physical vapor deposition and plasma-assisted chemical vapor deposition techniques and tribological properties were derived from reciprocating sliding tests of the coatings against alumina balls. Three types of wear particles were identified by electron diffraction and energy dispersive X-ray spectroscopy: nanocrystalline rutile (TiO₂), nanocrystalline graphite and microcrystalline graphite. Low coefficients of friction, of the order of 0.2, were attributed to the formation of solid lubricant films of sub-stoichiometric TiO_2-x Magnéli phases and/or graphite.     

Dry-Film Lubricants from Molybdenum Disulfide Bonded with Microfibrous Boehmite

Binders that have been tried for powdered, lamellar, dry lubricants have shortcomings such as hindering the realignment of the lubricant particles or encapsulating the lubricants, making a wearing-in process necessary. A microfibrous form of colloidal alumina (boehmite) is shown to act as a superior nonencapsulating binder for molybdenum disulfide in the formation of ductile, water-resistant dry lubricant films. Such films exhibit lower coefficients of friction than have been reported for molybdenum disulfide or graphite films bonded with any other material. These new lubricating coatings have good load-carrying ability and durability at any temperature below the thermal decomposition temperature of molybdenum disulfide (700 F). Optimum performance of these boehmite-bonded films is obtained when: (a) the weight ratio of fibrillar boehmite to MoS₂ is near 0.20; (b) the film is 0.2 to 0.5 mil thick; (c) the substrate is hard and highly polished; and (d) the film is applied as an alkaline dispersion (pH = 10) and then dehydrated by baking at 550 F.     

NBR Powder Modified Phenolic Resin Composite: Influence of Graphite on Tribological and Thermal Properties

The incorporation of graphite as a solid lubricant in the formulation of brake friction material is well-recognized practice. However, achieving the desired level of performances using graphite is still a significant challenge, due to difficulty in dispersion and loading of graphite in composite materials. The present investigation was aimed at identifying the effect of graphite loading on the tribological and thermal properties of a composite made from phenolic resin modified with powdered acrylonitrile butadiene rubber (NBR). Five composites were prepared with different proportions of graphite (0–40 phr) to the phenolic resin. Thermogravimetric analysis (TGA) and thermal conductivity measurements were carried out to demonstrate the thermal stability and thermal conductivity behaviors. Both the thermal stability and thermal conductivity were found to increase with an increase in graphite content. On the other hand, the tribological properties were found to be optimum at a definite loading of graphite (30 phr). The change in surface morphology of these composites was studied before and after the friction test and correlated with the tribological properties. This investigation provides guidelines for achieving a high-performance composite using graphite for brake friction materials.     

热喷涂宽温域耐磨自润滑涂层研究现状与展望

在航空、航天、冶金、电力、石化、矿采等领域,零件高温摩擦磨损特性是影响装备寿命的重要因素,在关重零部件表面设计制备宽温域耐磨自润滑涂层是装备零件强化改性和再制造修复的重要手段。首先阐述了宽温域耐磨自润滑涂层设计中过渡层、基础相、增强相的材料选择依据;其次针对单一固体润滑剂适用温度范围窄的问题,梳理了从低温润滑剂发生氧化反应原位生成高温润滑剂,低温润滑剂与高温润滑剂长时协同作用,添加抑制剂减缓润滑相的损耗退化等三种宽温域耐磨自润滑涂层材料设计方法;而后总结了宽温域耐磨自润滑涂层的制备工艺,分析了不同喷涂工艺的技术特点和涂层制备实例,介绍了宽温域耐磨自润滑涂层在军事装备和工业设备上的典型应用;最后在此基础上对宽温域耐磨自润滑涂层的未来发展方向进行了展望。     

石墨干膜润滑剂在碳钢表面摩擦磨损性能试验研究*

传统油或脂润滑剂在极端工况环境下无法满足碳钢类零件的减摩要求,采用干膜润滑剂是提高极端工况环境下碳钢表面摩擦磨损性能的可行性方法。采用超声波分散方法制备以石墨粉末为基体的干膜润滑剂,使用压力喷涂技术使其沉积在碳钢试件表面,在端面摩擦试验仪中开展干摩擦和石墨干膜润滑剂润滑下摩擦磨损性能对比性试验研究。试验结果表明：石墨干膜润滑剂在碳钢表面的沉积效果较好,沉积的石墨干膜润滑剂具有较好的润滑性能,可以有效地保护碳钢表面不被过度磨损;喷涂石墨干膜润滑剂的碳钢试件的工作寿命随着压力载荷和主轴转速的增大而缩短,负载和滑动速度的联合作用会加速涂层向稳定方向的过渡;磨损过程中形成的微观润滑剂颗粒会形成颗粒流润滑,适当添加石墨颗粒粉末可能会延长润滑剂正常发挥减摩作用的时间。制备的石墨干膜润滑剂为碳钢在极端工况环境下的减摩提供了支持。     

Microstructure,tribological and mechanical strengthening effect of multiphase Zn/ZrO<Subscript>2</Subscript>-SiC electrodeposited composite coatings

In an attempt to improve the mechanical and thermal resilient properties of mild steel, Zn-ZrO₂-SiC composite coating was fabricated from zinc-based sulphate electrolyte with incorporated composite particles of ZrO₂/SiC at 2.0 A/cm² for 10 min. The effects of particle on the mechanical properties were examined using scanning electron microscope attached with energy dispersion spectroscopy and atomic force microscopy. The micro-hardness and wear resistance behaviour were determined with high diamond micro-hardness tester and three body abrasive MTR-300 testers with dry sand rubber wheel apparatus with 5 N. The fabricated coating was thermally heated at 200 °C for 4 h to evaluate the coating stability. From the results, a modification in the microstructure and topographic orientation as a result of incorporated composite was noticed on the zinc matrix. The mechanical and thermal properties were observed to be considerably improved by the incorporation of the ZrO₂/SiC weight fraction. A significant improvement in wear and hardness properties were also obtained for the multiphase embedded coatings.     

Wear Behavior of Bronze Hybrid MMCs Coatings Produced by Current Sintering on Steel Substrates

In this work, a bronze matrix (90 wt% Cu + 10 wt% Sn) was reinforced with SiC and graphite particulates using mechanical alloying and a subsequent current sintering technique. The mechanically ball-milled bronze hybrid matrix composite powders reinforced with 5.0 wt% SiC and 5.0 wt% graphite were cold-compacted on a 1040 steel substrate under a pressure of 300 MPa. The compacted structure was sintered at atmospheric conditions to nearly a full density within 10 min using current sintering, in which the powders were heated by a low voltage and high current and compressed simultaneously. The samples were sintered at three different applied currents (1,500, 1,700, and 1,900 A) to provide dense and well-bonded coatings on steel substrates. Microhardness testing and optical and scanning electron microscopes (SEM) were used for microstructural characterization of the hybrid composites. The tribological characterization of the resulting composites was tested by a block-on-disk method for determination of the wear loss and friction coefficient behaviors against a steel disk. It was pointed out that increasing applied current during the sintering/coating process resulted in obtaining high-hardness and wear-resistant hybrid composite coatings.     

耐磨铜合金的研究现状与发展趋势

机械设备高速度化及高性能化的发展要求耐磨铜合金具备更高的强度和更优异的耐磨性能.传统的铝青铜系、锰黄铜系和铅黄铜系等合金的性能虽已有所提升,但因受材料自身特性、加工工艺、环境保护等因素制约,其应用范围受限.从制备工艺、性能、应用领域等方面介绍了具备较高开发价值的Cu-Ni-Sn系、Cu-Al2O3系、Cu-Nb系、Cu...     

Boundary Lubrication of Steel Surfaces with Borate,Phosphorus, and Sulfur Containing Lubricants at Relatively Low and Elevated Temperatures

Prolonging the life of engineering components through lubricant formulation to achieve better wear resistance and higher oxidation stability is of paramount importance to many mechanical systems, such as automotive gears and bearings. This can be accomplished with formulated lubricants that limit the generation of wear debris causing severe abrasion and protect the contacting surfaces through the formation of wear-resistant tribofilms. In this study, a ball-on-disk tribometer was used to characterize the friction and wear properties of steel surfaces slid in the boundary lubrication regime. An experimental scheme was developed to allow the statistical screening of various lubricant formulations. Sliding experiments were performed in baths of different lubricants at relatively low and elevated temperatures, approximately 32 and 100°C, respectively, under conditions of constant load and sliding speed. Surface profilometry, optical microscopy, and scanning electron microscopy were used to characterize the dominant friction and wear mechanisms. The tribological properties were found to strongly depend on the temperature and the additives (e.g., borate, phosphorus, and sulfur) present in the blended lubricants. The superior high-temperature wear performance of the lubricant with the higher borate content is indicative of the formation of a durable tribofilm that reduces metal-to-metal adhesion, material transfer, and surface plowing by wear debris.     

The tribological properties of bronze–SiC–graphite composites under sea water condition

Bronze–SiC–nickel coated graphite composites were fabricated by powder metallurgy technique (P/M). The tribological properties of composites sliding against AISI321 stainless steel pin were studied under sea water condition. The graphite is an effective solid lubricant in sea water environment. The SiC improved the hardness and tribological properties of composites. The friction coefficient of bronze–SiC–graphite composites increased with the increase of SiC. However, the specific wear rate of bronze–SiC–graphite composites decreased with increasing SiC. Bronze-2 wt% SiC-11.7 wt% nickel coated graphite composite showed the best tribological properties due to the synergistic effects of reinforcements.