Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition （PVD） TiN coatings were used, such as, in-lined （IN） and staggered （ST） spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of-180 V and slid for 4, 8 and 11 h respectively, were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.     

Fretting wear of steel wires in hoisting ropes

To investigate the fretting wear of steel wires in hoisting ropes, specimens were made of 6 × 19 point contact ropes. A model for the fretting wear was developed and a fretting wear test rig was designed in laboratory. A series of experiments were performed on this test rig. The wear volume was taken as a characteristic parameter to describe the fretting wear in relation to the contact load, reciprocating cycles and amplitude. Moreover, the wear mechanisms were discussed in the fretting process.     

Effect of Carbon Nanotube on the Oscillating Wear Behaviour of Metal-PTFE Multilayer Composites

Two kinds of metal-PTFE multilayer composites, which were composed of a steel backing, a middle layer of sintered porous bronze and a surface layer of polytetrafluoroethylene(PTFE) filled by carbon nanotubes(CNTs) or not, were prepared. The wear properties of metal-PTFE multilayer composites oscillating against 45 carbon steel under dry condition were evaluated on an oscillating wear tester, and the effect of CNTs on wear behaviour of metal-PTFE multilayer composites was studied. The results showed that the worn surface of metal-PTFE multilayer composites was characterized by adhesive wear, abrasive wear and fatigue wear. The CNTs greatly increased the adhesion strength of PTFE in the metal-PTFE composites and thereby greatly reduced puck, ploughing, and fatigue failure of PTFE during wearing. The PTFE filled with CNTs prevented direct contact between the mating surfaces and served as fine self-lubricating film, in which the oscillating wear mechanism of the composites was changed to a slightly adhesive wear. Therefore, the CNTs significantly decreased the weight loss and obviously increased the wear resistance of metal-PTFE multilayer composites.     

中性环境中锈斑对X70/X80钢早期腐蚀的作用

采用NS4典型中性土壤模拟溶液模拟中性土壤环境,将X70和X80管线钢电化学试件在模拟溶液中进行短期浸泡,发现溃疡状锈斑均匀分布在试件的工作表面,锈迹疏松易脱落,微观呈现颗粒状形貌,面积较大的锈斑处出现浅腐蚀坑。对带锈件和不带锈件进行了极化曲线、交流阻抗等电化学实验并进行了对比。对比结果发现,金属界面早期锈斑的产生加重金属的腐蚀,加快腐蚀速率。这是因为早期锈斑的不完整性与稀疏性降低金属基体与腐蚀环境电化学反应的极化电阻,其粗糙的表面增加试件的工作面积,增大腐蚀电流。     

Elements inter—diffusion in the turning of wear—resistance aluminum bronze

Inter-diffusion of elements between the tool and the workpiece during the turning of aluminum bronze using high-speed steel and cemented carbide tools have been studied.The tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novel high strength,wear-resistance aluminum bronze without coolant and lubriant,Adhesion of workpiece materials was found on all tools‘ surface.The diffusion couples made of tool materials and alumium bronze were prepared to simulate the inter-diffusionn during the machining,The results obtained from tool wear samples were compared with those obtained from diffusion couples.Strong inter-diffusion between the tool materials and the aluminum bronze was observed in all samples.It is concluded that diffusion plays a significant role in the tool wear mechanism.     

含氮量对GCr15轴承钢机械性能的影响

本文采用以纯度99.99%的氮气代替氩气由钢包底部的多孔透气砖吹入钢包来精炼 GCr15轴承钢的新工艺,获得了三个不同含氮量水平的 GCr15钢试样.以研究含氮量对该钢机械性能的影响。做了接触疲劳试验—磨损试验和平面应变断裂韧性试验。结果表明,含氮量对滚动接触疲劳寿命及平面应变断裂韧性具有很显著的影响,而对耐磨性影响很小.     

粗糙软接触润滑的摩擦因数

以刚性球在PDMS圆盘上运动为背景,建立了润滑条件下的软接触数学模型,通过数据处理将接触表面粗糙度的测量结果耦合到数学模型中,并根据接触时不同润滑区域的特点,提出了整体名义接触区域的摩擦因数计算模型,利用现有实验数据验证了模型的有效性。在不同润滑条件下计算并分析表面粗糙度在软接触中的作用。当润滑油的卷吸速度与黏度的乘积(μη)值较低时,流动的润滑油与微凸体间的相互作用产生的压力增量使摩擦因数显著增加。     

评定钢丝的微动摩擦磨损参数研究

以点接触式提升钢丝绳为研究对象，在实验室建立了钢丝绳中钢丝的微动磨损模型．在自制的钢丝微动磨损试验机上进行微动磨损实验，考察了接触载荷、微动时间和振幅的变化对钢丝试样磨损深度的影响，并用综合参数pv值和pvt值评定微动磨损深度的变化．结果表明，相同微动时间下磨损深度随pv值的增加而增大，相同接触载荷下磨损深度随pv值增大而减小，磨损深度和综合参数pvt值之间基本成线性关系．同时通过微动过程中摩擦系数的变化、磨损产生的磨屑以及磨痕形貌，分析微动磨损过程中磨损机制随微动实验条件的变化规律。     

冷扎Q235钢/激光熔覆合金钢摩擦磨损

通过对9SiCr钢表面进行合金激光熔覆处理,在摩擦磨损实验机上对熔覆合金钢与Q235钢配副进行了摩擦磨损性能实验.通过摩擦磨损实验研究了参数如载荷、滑动距离、滑动速度、润滑条件等对Q235钢与熔覆合金钢的磨损量的影响,熔覆合金钢与Q235钢的磨损量与压力和滑动速度成正比.Ni合金钢的耐磨性比Co合金钢要好.通过扫描电镜分析了熔覆合金磨损机理,熔覆合金钢磨损主要以磨粒为主,同时表面存在大量凹坑,而Q235钢以磨粒和塑性变形为主.     

GCr15球-盘点接触摩擦副的滑滚摩擦磨损特性研究

选用GCr15钢盘和GCr15球作为摩擦副,在NGY‐6纳米润滑膜测量仪上开展球‐盘点接触摩擦副在润滑状态下的滑滚摩擦磨损实验,研究不同接触应力、钢球转速、滑滚比等参数对摩擦副的摩擦因数、磨损形貌的影响规律．结果表明：当接触应力和钢球转速一定时,摩擦因数随着滑滚比的增大而逐渐增加后达到稳定状态;当滑滚比一定时,摩擦因数随接触应力的增大而逐渐增大;当钢球转速低于300 r／min时,摩擦因数随着钢球转速的增大而减小;当钢球转速高于300 r／min、接触应力大于0．84 GPa时,摩擦因数随着钢球转速的增大而呈增大趋势．Stribeck曲线表明：当滑滚比为0．01时,摩擦副处于流体动压润滑状态;当滑滚比为0．03时,润滑状态随Sommerfield参数的增加而从边界润滑过渡到混合润滑;当滑滚比分别为0．05、0．1、0．3、0．5时,润滑状态为边界润滑．滑滚比较小时,磨损机制以疲劳磨损为主,随着滑滚比的增大,磨损机制转变为磨粒磨损．     

润滑油黏度对高速球轴承性能及损伤的影响

为探究高速工况下润滑油黏度对轴承润滑状态及性能的影响,试验研究了Si_3N_4陶瓷和GCr15轴承钢材质的7014C型角接触球轴承在不同润滑油黏度条件下的温升和振动特性.结果表明,轴承温升及振动随润滑油黏度的增大呈现出先下降后上升的趋势,影响程度随转速的增大而增大.同时,陶瓷轴承较钢制轴承在不同润滑油黏度条件下均表现出更优越的性能.将试验结果与轴承润滑状态分析结合,讨论了润滑油黏度、润滑状态、轴承性能三者的关系,为高速角接触球轴承适用润滑油黏度的选择提供了重要依据.此外,本文还对不同润滑条件下的轴承滚动面损伤进行了分析.结果显示,全膜弹流润滑条件下,陶瓷轴承与钢制轴承滚动面损伤较小且差异不明显.部分膜弹流润滑条件下的轴承滚动面损伤严重,表面出现大量凸峰和凹谷,轴承滚动体及外滚道表面损伤较内滚道严重,钢制滚动体的表面划痕较陶瓷滚动体密且深.     

磨浆机磨盘失效分析及新磨盘钢的研制

失效分析查明，造纸工业中磨浆机磨盘的失效是磨粒和粘着磨损、冲蚀、断裂和塌陷等失效形式单独或交互作用的结果。在此基础上，根据其服役性能要求，设计了新磨盘材料──含稀土中锰钢，具有优良的强度和韧性配合。模拟试验表明，在中、低应力水平磨损条件下，新磨盘钢易发生形变诱发马氏体相变。具有较高的加工硬化能力和优良的耐磨性能。     

The Friction and Wear of Sleeve-ring Pair Lubricated by Active Lubricants in the Presence of Magnetic Field

1　IntroductionTribologicalphenomenoncanbeseenintheopera tionsofequipments ,instruments ,units ,andsoon .Theinvestigationonthemagnetictribologyattractsbroadinter estsoftribologicalworkers ,andthesignificantexplorationsonthetheoreticalandapplicationhavecarriedout .Thefrictionreductionandwearpreventioninthepresenceofmagneticfieldareconsideredtobetheincreaseofmicro hardnessontherubbingsurfaceandtheoxidationofoxy genonthewearsurfaceatthedryfrictionofatmosp here[1 4] .Theperformanceofboundarylubric…     

45钢稀土氮碳硼共渗层的摩擦学性能研究

采用AMSLER型磨损试验机，在油润滑条件下，对经稀土氮碳硼和氮碳硼共渗的45钢进行滑动磨损试验，研究了渗层的组织结构及硬度对45钢耐磨性的影响，并探讨了共渗层的磨损机制．结果表明，45钢稀土氮碳硼共渗处理后抗磨性能提高3～4倍，摩擦系数减小近2倍；共渗层硬而脆的特点使其在摩擦接触应力的作用下发生塑性变形破坏．     

M2高速钢强脉冲离子束表面改性及其耐磨耐蚀性

针对陶瓷梯度涂层性能优良,在大气氛围下等离子喷涂制备涂层会受到空气氧化这一情况,在可控气氛（Ar气）中采用等离子喷涂的方法制取了NiCrBSi/Al₂O₃的梯度涂层,并且与大气条件下制取的NiCrBSi/Al₂O₃的梯度涂层进行对比.借助扫描电子显微镜（SEM）、x 射线衍射仪（XRD）对涂层的组织分布、相结构进行分析.结果表明：在Ar气和大气中梯度涂层的组织内部都没有明显的界面,实现了组织的连续变化;在Ar气中制取的梯度涂层的组织更加致密,被氧化的程度更低,质量更好.     

纳米烟炱颗粒作为添加剂在激光刻蚀织构表面 的摩擦学性能研究

通过激光刻蚀法制备不同织构表面,在UTM-2摩擦磨损试验机,采用球-面接触方式往复运动,考察了纳米烟炱颗粒作为润滑油添加剂的摩擦磨损性能。借助高分辨透射电镜、三维轮廓仪、扫描电镜和拉曼光谱仪等测试设备,分析了其纳米烟炱颗粒在织构表面的摩擦学机理。结果表明: 部分织构会增加摩擦系数,但磨损率却显著减小;织构的面积率越高,抗磨性能越优异。纳米烟炱颗粒加入后,试样的磨损明显减轻,这归因于烟炱颗粒的自润滑性能以及织构微坑储存纳米颗粒、润滑油的功能。表面织构与纳米烟炱颗粒的共同耦合作用展现出了优异的抗磨减摩性能。     

纳米级镍粉改善润滑油摩擦磨损性能的研究

在MHK－500型环块摩擦磨损试验机上,研究了纳米级金属镍粉（直径在10～50nm）加入到矿物油中的润滑性能,结果表明：在低中滑动速度下（滑动速度分别为1．285m／s和2．57m／s）,加有纳米级镍粉的润滑油表现出优良的抗磨性能．     

石墨密封材料润滑膜形成规律及摩擦磨损研究

为了研究石墨密封材料润滑膜形成规律及其摩擦磨损特性,使用MMW-1立式万能摩擦磨损试验机分别对浸渍金属锑、浸渍树脂和人造石墨多组试样进行摩擦磨损试验.研究表明:浸锑石墨密封材料呈现快速成膜、迅速稳定的有膜润滑状态,其摩擦系数在0.08左右;浸树脂石墨密封材料因材料硬度不同而呈现有膜润滑、贫膜润滑和残膜润滑状态,摩擦系数为0.07～0.1;人造石墨表现为无膜润滑,摩擦系数在0.25左右.有膜摩擦耐磨损性能最好,贫膜摩擦耐磨损性能不稳定,无膜摩擦磨损严重.     

PTFE和MoS_2填充尼龙复合材料摩擦行为研究

以注塑成型法制备了聚四氟乙烯(PTFE)和MoS2填充PA1010复合材料,采用M-2000磨损试验机考察了复合材料与45钢对摩时的摩擦磨损性能,并利用扫描电子显微镜(SEM)分析了PA复合材料磨损表面及其偶件表面转移膜形貌。研究结果表明:PTFE填充PA1010可显著改善尼龙复合材料的摩擦磨损性能。PTFE质量分数为25%时,复合材料的摩擦学综合性能最佳。PTFE和MoS2共同填充PA1010时,复合材料的摩擦因数和磨损率随着PTFE含量的减少、MoS2含量的增加,整体呈现增大趋势,其中PA+20%PTFE+5%MoS2复合材料的减摩抗磨性能较好。在正常工作条件下(0.21-0.42 m/s,100-300 N),PA+25%PTFE复合材料的抗磨性优于相同条件下PA+20%PTFE+5%MoS2复合材料,但PA+20%PTFE+5%MoS2复合材料具有更宽的速度适用范围。PA复合材料的摩擦磨损性能与其在偶件表面形成的转移膜的特性有重要关系,转移膜的厚度大小、分布均匀状况以及和偶件的结合强度都会对复合材料的减摩抗磨性能产生影响。     

微观点蚀机理的研究

由于有的齿轮在失效过程中,同时存在有宏观点蚀及微观点蚀两种不同的失效形式,为了弄清微观点蚀和宏观点蚀的关系,因此采用18Cr_2Ni_4W_A渗碳滚轮试样进行了接触疲劳性能试验。通过试验,发现试样的表面粗糙度对试样的失效形式是有影响的。并从表面粗糙度,油膜厚度及力学条件等方面,论证了微观点蚀和深层剥落两种失效形式的形成条件、微观点蚀的成因和发展过程,而且提出了微观点蚀发展成宏观点蚀的机理。