【作者】 莫云辉；

【导师】 陶德华； 韦习成；

【作者基本信息】 上海大学 ， 机械设计与理论， 2010， 博士

【摘要】 由于微纳米润滑材料和技术在解决机械零部件磨损自修复、延长其使用寿命和减少能源消耗具有的重要意义,设计新型润滑体系日益受到国内外的广泛关注。但由于纳米微粒的制备成本高、在润滑油中的分散稳定性较差、修复涂层中单质金属的成分较低、修复涂层的厚度较薄(一般为几十纳米)、以及修复技术较复杂等问题,限制了其广泛应用。针对上述问题,本文采用活化技术,重点研发了工艺简单、能修复较严重磨损表面、有良好润滑、减摩和抗磨功能且环境友好的、含微纳米软金属(锡、锌、铝锡、铝锡锌、锌锡、铟锌锡)的一系列新型润滑剂,并基于钢-钢、钢-铜摩擦副,考察了其修复性能和摩擦学特性。采用XPS、AES、SEM、淬冷、划痕、拉伸、弯曲、原位纳米力学等测试手段,分别研究了修复涂层的成分、厚度、结合强度、表面接触应力。探讨了润滑剂的摩擦修复作用机理,通过台架试验考察了其在机械传动中的应用前景。取得如下成果：用活化技术和机械法研制了粒径小于100nm的活化纳米锡润滑油,用于铜表面摩擦试验。SEM分析显示,该修复润滑剂在铜表面原位摩擦生成了10μm～20μm厚的修复涂层,涂层与基体结合紧密。XPS和AES分析表明,涂层中富含锡,Sn的原子百分比浓度最高达90%,具有优良的减摩抗磨性能。试验证明了活化添加剂对修复质量的重要影响。采用00号半流体脂代替32号基础油,解决了添加剂微粒在润滑油中的分散不稳定性。研制的20%活化微米锡半流体脂,在铜表面摩擦生成了20μm厚的Sn涂层,在各种载荷的摩擦试验中均显示负磨损,减摩性和抗磨性比传统抗磨剂3%ZDTP、3%氯化石蜡平均提高了32%、23%和148%、423%。研制的含锌和锌锡复合活化润滑脂有良好的修复性能和摩擦学性能,在铜基体上摩擦生成了10μm厚的锌涂层和20μm厚的锌锡涂层。锌锡的协同效应使该脂在各种载荷条件下的减摩抗磨性能明显优于单锌脂。研制的含铝系列润滑脂,能在铜基体上摩擦形成厚度为15μm的铝锡涂层和25μm的铝锡锌涂层,Al、Sn、Zn分布在整个修复涂层并渗镀进入铜基体。显示了活化的Al-Sn和Al-Sn-Zn添加剂之间具有良好的互配性和协同性以及与摩擦副的优良匹配性。攻克了目前添加剂难以在钢表面生成较厚修复层的难题。利用几种添加剂间的综合效应和协同增效作用,制备出活化锌锡和铟锡锌增效修复润滑剂,有效地修复了受损的钢摩擦副表面,锌锡和铟锡锌修复涂层的厚度分别达20μm和30μm。润滑修复后的钢-钢摩擦副,在各种载荷和各种转速下均呈现负磨损,在高转速下有稳定的低摩擦系数。用淬冷试验和划痕试验测试了涂层的结合强度。试验后的涂层无局部起皮、鼓泡、撕裂和脱落,涂层与基体结合牢固。考察了试样在拉伸和弯曲时对涂层结合性能的影响,当拉伸位移为2.7～3.6mm、弯曲变形为3.2～5.6mm时,未见涂层滑移、破裂、拱起和剥落,涂层与基体的固结性能良好。用纳米压痕法研究了各修复涂层的弹性模量等微观力学性能,由此分析计算了钢-钢直齿圆柱齿轮传动和钢蜗杆与铜蜗轮传动修复齿面的接触应力。研究表明,修复后的表面性能得到优化,能较大幅度地降低表面接触应力。在此基础上,将研制的5In25Sn15Zn脂与00号对比脂分别用于WD33-20型蜗轮减速器进行了台架试验。使用不含添加剂的00号脂润滑的蜗杆和蜗轮齿面均发生了明显磨损,采用5In25Sn15Zn润滑脂后,脂中Fe和Cu的浓度显著下降,蜗杆蜗轮的磨损得到有效控制,且齿面损伤部位已基本修复,减速器的机械效率大幅提高,显示了研发的修复润滑剂的潜在应用前景。更多还原

【Abstract】 Since micro-nanometer lubricating material and technique possess significant meaning to machine parts in wear repairing, prolonging working life and reducing energy consuming, it is an increasing tendency for scientists to design novel lubricating system. But existed problems, such as higher cost to prepare nano-particulates, unstable decentralization, lower composition of elementary metals in repairing coatings, more thin coating thickness (as decades nanometers) and complicated repairing techniques and so on, restricted its application. This paper focus on researching and developing a serious of novel lubricants with activating method, which contained micro-nanometer soft metals, such as Sn, Zn, Al, Al-Sn, Al-Sn-Zn, Zn-Sn, In-Zn-Sn and so on. These new types of lubricants were in characteristics of simplifying preparing techniques, repairable to relatively serious worn surface, good lubricating, friction-reducing and anti-wear performance, and environment friendly properties. Based on steel-steel and steel-copper tribo-pair, their repairing behaviors and tribological properties were investigated. By means of X-ray Photoelectron Spectrum (XPS), Auger Electron Spectrum (AES) and Scanning Electronic Microscope (SEM), cooling quenching and nick, extend, bend testing, and Nano Mechanical Test Instruments, the composition, thickness, combining intensity, contact stress of the coatings were researched separately. The friction repairing action mechanism of the carried out lubricants were studied and analyzed. Furthermore, the applications foreground of lubricants used in mechanical transmission were also evaluated with frame testing. The results were as follows:Activated Nano-Tin lubricant was carried out with activating techniques and mechanical preparation, its particles diameters were below 100nm. The Nano-Tin lubricant was used for copper surface friction test. SEM showed that the repairing coating with thickness about 10μm-20μm has been created on the copper surface by the repairing lubricant under the action of mechanical and friction force. The coating was combined tightly with the substance. XPS and AES analytical results indicated that the coating contained rich Sn and its concentration of atom percentage of Sn could reach to 90% at tiptop. This explained why the coatings possess excellent friction-reducing and anti-wear capabilities. The test also proved the important effect of activated additives on repair quality.No.32 basic oil was replaced by No.00 semi-liquid grease to resolve dispersibilities instability and sedimentation of the additive particulates in the lubricating oil. The prepared semi-grease contained 20% activated micrometer Tin, which formed 20μm Sn coating on the cooper surface under friction, always displayed negative wearing characters under various loading conditions, its friction-reducing and anti-wear properties were average higher 32%,23% and 148%,423% separately than traditional anti-wearing lubricants of 3%ZDTP and 3% chlorinated paraffin.Zn kind and Zn-Tin Compound activated lubricating grease were developed that possess good repairing character and tribological performance. Zn coating with 10μm thickness and Zn-Sn coating with 20μm thickness were created on the copper substance under friction. Integrating effect of Zn-Sn let its friction-reducing and anti-wear characters exceeded than Zn grease evidently under various loading conditions.A1 kind of lubricants were explored that could create Al-Sn coating with 15μm thickness and Al-Sn-Zn coating with 25μm thickness on copper substance under friction. Al, Sn and Zn distributed on entire coatings and seeped plated into the copper base. It implied the mutual fitting performance and synergisms of activated additives of Al-Sn and Al-Sn-Zn, and the good matching capabilities with tribo-pair.Difficult problem that additive was hard to form repairing coating in considerable thickness on steel surface was solved. Through integration effect and synergisms under the action of several additives, the effective repairing lubricants with activated Zn-Sn and In-Zn-Sn were carried out. The worn steel surface was repaired efficiently. The coating’s thickness of Zn-Sn and In-Zn-Sn were 20μm and 30μm separately. The steel-steel tribo-pair after lubricating repairing was always displayed negative wear situation under various loads and rotating conditions, and low friction coefficient characteristic was showed stably at high rotation speed.The combination intensity of the coating was tested through cooling quenching and nick test. The coatings after test there were no crinkling, bullate, avulsion and break off, the combination between the coating and base was eligibility. The affecting to coatings when sample under tension and bending were reviewed. The concretion capability between the coating and base was good under 3.2-5.6mm of bending distortion and 2.7-3.6mm of tension displacement. The micro mechanical properties were analyzed by nano-indentation technique. The surface contact stress of the repaired teeth in the steel-steel spur gear transmission and steel worm against copper wormgear transmission were calculated and analyzed. The study indicated that the exterior performance of those repaired surface was optimized and contacting stress on teeth surface could depress obviously.On the basis above, the frame testing was performed on the WD33-20 type of wormgear reducer with the carried out 25Sn15Zn5In grease and No.00 contrast grease separately. Worn occurred on the teeth surface of worm and wormgear when use No.00 lubricating grease with no additives. When replaced by 25Snl5Zn5In lubricants, the Fe and Cu concentration in the grease reduced sharply. It means that the abrasion of worm and wormgear has been controlled effectively, and the damnifyed area on the teeth surface has been repaired basically. The mechanical efficiency of the reducer was advanced greatly. It was showed that the developed repair lubricants possess potential application foreground.更多还原