烃分子添加剂在公交车两用燃料发动机油中的摩擦学试验研究

为了提高公交车两用燃料发动机油的摩擦性能,将烃分子添加剂加入 CNG/汽油两用燃料机油中,采用四球摩擦磨损试验机和梯姆肯试验机,考察其对 CNG/汽油两用燃料机油摩擦性能的影响,利用 SEM表面分析技术对摩擦副表面进行了磨损机理分析.试验表明:烃分子添加剂对CNG/汽油两用燃料机油摩擦学性能有所提高,对摩擦副表面具有修复平整作用     

含钐纳米粒子的抗磨减摩性能研究

用溶剂取代干燥法制备了粒径为20－40mm的纳米晶硼酸钐粒子,并用TEM及XRD对该产物进行了表征。用四球机及环块摩擦磨损试验机测定了纳米硼酸钐作润滑油添加剂的摩擦这性能,研究发现：纳米硼酸钐的加入,能有效提高500SN基础的抗磨减摩性能及承载能力,且纳米硼酸钐的加入量有一最佳值,超过此量,含纳米粒的润滑油摩擦学性能下降,纳米硼酸钐的摩擦学作用,机理是在摩擦表面形成沉积膜和渗透膜,沉积膜和渗透膜的共同作用使润滑油的摩擦学性能提高。     

Ni60A/MoS_2复合涂层润滑膜的形成及自修复机理

通过考察等离子体喷涂Ni60A/MoS2复合润滑涂层的摩擦学特性,探讨了复合涂层中MoS2润滑膜的形成及自修复作用,讨论了影响MoS2润滑膜形成过程及其润滑和减摩抗磨性能的因素,进而建立了用于说明润滑膜形成及破坏过程的物理模型。结果表明:润滑涂层润滑膜的形成机理包括摩擦开始、MoS2析出表面、MoS2覆盖表面和MoS2表面膜形成等4个阶段.润滑涂层润滑膜的破损过程包括膜的厚度不断减小、裂纹的产生、裂纹的扩展和润滑膜的剥落4个阶段.同时,硬质颗粒刺入润滑膜并导致润滑膜擦伤,从而大幅降低润滑膜的寿命,其降幅接近一半.     

有机粘结固体润滑膜研究进展

分析了有机粘结固体润滑膜的减摩耐磨主要机理,详细讨论了环氧与酚醛环氧、聚酰亚胺与聚酰胺酰亚胺、聚苯硫醚和聚酰胺等常用高分子树脂基体固体润滑膜的摩擦学特性及其性能,展望了高分子固体润滑膜的发展趋势和研究方向.     

Tribological behavior of hot-pressed boron carbide with oxidation

Ｈｏｔ ｐｒｅｓｓｅｄｂｏｒｏｎｃａｒｂｉｄｅｅｘｈｉｂｉｔｓａｌｏｗｄｅｎｓｉｔｙａｓｓｏｃｉａｔｅｄｗｉｔｈｈｉｇｈｓｔｒｅｎｇｔｈ ,ｈａｒｄｎｅｓｓａｎｄｗｅａｒｒｅｓｉｓｔａｎｃｅ .Ｉｔｉｓｑｕｉｔｅｐｒｏｍｉｓｉｎｇｆｏｒｓｔｒｕｃｔｕｒａｌａｐｐｌｉｃａｔｉｏｎｓ[1,2 ] .Ｂｏｒｏｎｃａｒｂｉｄｅｉｓｏｎｅｏｆｔｈｅｍｏｓｔｓｔａｂｌｅｃｏｍｐｏｕｎｄｓ.Ｉｔｉｓｎｏｔａｔｔａｃｋｅｄｂｙｃｏｌｄｃｈｅｍｉｃａｌｒｅａｇｅｎｔｓ.Ｈｏｗｅｖｅｒ,Ｂ4Ｃｍａｔｅｒｉ ａｌｈａｓｂｅｅｎｕｓｅｄ…     

磁场作用下锰锌铁氧磁流体承载能力试验研究

通过对MS-800四球试验机油杯的改进,在测试区域内产生可调磁场;利用改进后的油杯在四球机上测定磁场作用下添加锰锌铁氧纳米磁性颗粒润滑油的承载能力.结果表明：外加磁场作用下,磁性液体的摩擦学性能得到较大改善,首先磁性液体黏度值随磁场强度的增强而增大,从而提高了添加锰锌铁氧体磁性颗粒润滑油的综合磨损值,最大可达基础液的1.43倍;其次纳米磁性颗粒中的Zn元素可使润滑油的最大无卡绞负荷PB值提高50%,烧结负荷PD值提高100%.     

Assessment model for tribological property of ceramic/stainless steel rubbing pairs in H2O2 solution

The tribological properties of ZrO2 ceramic and 1Cr18Ni9Ti stainless steel rubbing pairs were investigated using a special tribo-tester under different concentrations of hydrogen peroxide (H2O2) solution.The comparison analyses of the friction coefficients,worn volume rates,worn particles and surface roughness were conducted under the tested conditions.There were significant differences of the tribological properties of the rubbing pairs in the different concentrations H2O2 solution because of oxidation and corrosion.This research has revealed that the main wear mechanisms between the rubbing pairs are severe adhesive wear,abrasive wear and corrosive wear in the H2O2 solution with different concentrations.A model has been established to assess the most suitable concentration of the H2O2 solution for the tribological properties of the rubbing pairs.The result shows that 50% concentration of the H2O2 solution is the most suitable.The assessment result is consistent with the experimental result.It is believed that the knowledge gained in this study is useful for the optimization of the friction pairs in the extreme condition.     

High temperature tribological behaviors of nano-diamond as oil additive

The tribological behaviors of the nano-diamond particles including the nano-diamond and the nano-diamond modified were studied at high temperature using SRV multifunctional test system. The worn steel surfaces were analyzed by means of X-ray photoelectron spectroscopy (XPS). The results show that nano-diamond particles can obviously improve the antiwear and friction reducing properties of the base oil at high temperature and the high load. The friction coefficient of the nano-diamond is very low at 200 °C when the test load is not more than 20 N. This tribological behaviors should attributed to the similarly to “ball bearing” lubrication action of the nano-diamond particles, so the movement between tribological pairs become sliding/rolling. The nano-diamond modified by dimer ester possesses excellent antiwear and friction reducing performance at 500 °C and load 500 N. The tribochemical reaction film between the nano-diamond particles and the renascent wear surface plays dominating lubrication role and the presence of the dimer ester on the rubbing surface can be propitious to form lubrication film containing nano-diamond on the worn surface at high temperature and high load. Foundation item: Project (51489020605JS9105) supported by National Key Laboratory for Remanufacturing     

The effect and mechanism of Nano-Cu lubricating additives on the electroless deposited Ni-W-P coating

The coating and deposition process with excellent anti wear and suitable for industrial application were developed, and the optimum bath composition and process were obtained by studying the influence of the bath composition, temperature and pH value on the deposition rate and the plating solution stability. Moreover, the tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and energy dispersive spectrometer. Research results show that Ni-W-P alloy coating and nano-Cu lubricating additive have excellent synergistic effect, e g, the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano-Cu additives) has increased hundreds times than 45 steel as the metal substrate with the basic oil, and zero wear is achieved, which breaks through the bottleneck of previous separate research of the above-mentioned two aspects.     

地铁弯道曲率半径对钢轨磨损的影响

根据赫兹接触理论,在JD—1型轮轨模拟试验机上通过改变钢轨曲率半径研究了曲线半径对地铁钢轨磨损的影响。实验结果表明:随着曲率半径的减小,钢轨磨损量增大,磨损深度和宽度均有所增加;钢轨曲率半径较小时,轮轨间存在蠕滑行为,钢轨承受的横向水平力和摩擦力均增大,这将导致钢轨接触面产生严重的塑性变形和表面硬化。     

On-line metallic wear diagnosis of unlubricated contacts by using self-generated voltage

0　ＩＮＴＲＯＤＵＣＴＩＯＮＦｏｒｆｒｉｃｔｉｏｎｂｅｔｗｅｅｎｍｅｔａｌｓ ,ｔｒｉｂｏｅｌｅｃｔｒｉｃｉｔｙｉｎｖｏｌｖｅｓｓｕｒｆａｃｅｃｏｎｔａｃｔｐｏｔｅｎｔｉａｌ,ｔｈｅｒｍａｌｅｌｅｃｔｒｉｃｐｏｔｅｎｔｉａｌ (Ｓｅｅ ｂｅｃｋｅｆｆｅｃｔ) ,ａｎｄｅｌｅｃｔｒｏｎｅｍｉｓｓｉｏｎ ,ｅｔｃ[1] .Ａｎｄｔｈｅｆｒｉｃ ｔｉｏｎｏｆｍｅｔａｌｓｕｎｄｅｒｌｕｂｒｉｃａｔｉｏｎｓｔａｔｅｓｍａｙｂｅａｃｃｏｍｐａｎｉｅｄｗｉｔｈｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｐｒｏｃｅｓｓａｎｄｅｌｅｃｔｒｏｋｉ…     

混杂增强AZ91复合材料的制备及其显微组织和性能

采用挤压铸造方法制备了以AZ91镁合金为基体、Al2O3短纤维(Al2O3f)和石墨颗粒(Grp)混杂为增强体的复合材料。观察了不同复合材料的显微组织,测试了其力学性能,并对其摩擦磨损性能进行了研究。结果表明:用此法制备的镁基复合材料增强相分布均匀,与基体结合紧密。硬度随Grp体积分数的增加而降低,Al2O3f的加入能提高复合材料的硬度。抗拉强度和伸长率都随Grp体积分数的增加而减小。Grp体积分数增加,磨损质量损失和摩擦系数都降低。随着摩擦过程的进行,在试样表面逐渐形成一层黑色连续的润滑膜。     

QPQ表面疏松层纯磨损试验研究

在M-2000型磨损试验机上进行纯磨损试验,研究了QPQ表面改性层在浸油擦干后的滑动干摩擦磨损过程。根据磨损曲线和摩擦系数的变化,发现其摩擦磨损过程存在一个干摩擦向边界摩擦过渡的亚稳定阶段,稳定阶段的磨损率和摩擦系数仅为未浸油干摩擦磨损试验时的三分之一。利用SEM分析各阶段磨损表面形貌,QPQ表面改性层磨合阶段的主要磨损机理为黏着磨损,亚稳定和稳定阶段对应的磨损机理为显微切削和划伤。试验结果表明,QPQ表面改性层外表面存在一定程度的疏松层可以储存润滑油,降低摩擦因数,避免或减轻了黏着磨损及磨粒磨损。     

LVQ神经网络分类器在润滑油磨粒识别上的应用

论述了一种用计算机图象系统进行磨粒识别的方法。该系统采用ＬＶＱ神经网络作为分类器来识别润滑油中磨粒的表面结构，从而确定机器的工作状况。识别过程包括４个阶段：（１）获取磨粒的铁谱图像；（２）将图像进行数字化并表提取特征；（３）对从特征集中提取的训练数据进行学习；（４）对磨粒进行识别并且生成机器运行状况的结果报告。对内燃机的滑动和滚动的几类磨粒进行识别的结果表明，这种方法可成功地用于磨粒识别。     

粘结石墨基固体润滑涂层的微动摩擦磨损性能

为了探讨粘结石墨基固体润滑涂层的微动摩擦磨损性能的作用机理,使用SRV微动摩擦磨损试验机对粘结石墨基固体润滑涂层在微动试验条件下的摩擦学性能以及抗承载能力进行研究,对其磨痕形貌和对偶转移膜进行分析。研究结果表明：粘结石墨基固体润滑涂层的磨损率随着试验载荷和摩擦速度的增大而减小;而摩擦因数随着试验载荷增大而减小,随摩擦速度增大而缓慢增大;在微动摩擦过程中,高载高速可以促进高质量转移膜在对偶表面形成,从而使得粘结石墨基固体润滑涂层具有良好的抗承载能力和优异的抗磨减摩性能。     

Effect of counterface materials on friction and wear behavior of double glow glasma discharge surface alloying on Ti22Al25Nb alloy

Samples of surface chromising layer were prepared by the double glow plasma discharge technique. X-ray diffraction and X-ray photoelectron spectroscopy(XPS) analysis of different elements confirmed the formation of chrome in the layer. Their tribological properties were investigated by pin-on-disk tribometer. Silicon nitride, GCr15, and nickel-based alloy were selected as counterface materials. Results indicated that the lowest friction coefficients and wear rate were obtained when substrate and chromising layer against nickel-based alloy, and tribological properties of chromising layer were better than those of substrate. The highest friction and wear rate were samples against silicon nitride alloys. In the case of three rubbing pairs, the unchangeable materials against different hardness counterfaces leaded to different wear mechanisms. Samples against silicon nitride exhibited abrasive mechanism, and when GCr15 and nickel-based alloy were used as counterface, transfer film and glaze layer formed on the contact surface, which played the main role in decreasing friction and wear. Funded by the Natural Science Foundation of Jiangsu Province China(No.BK2005128), and the Scientific Research Foundation of Nanjing University of Information and Technology     

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。     

TC4钛合金表面微织构干摩擦特性

为改善TC4钛合金表面摩擦学性能,采用皮秒紫外激光技术在TC4钛合金表面加工了3种形状的微织构。使用多功能摩擦磨损试验机研究了织构化TC4钛合金在多接触条件下的摩擦学特性,并采用显微硬度仪、扫描电镜、激光共聚焦显微镜对织构化TC4钛合金的表面硬度、表面粗糙度、磨痕三维轮廓和磨痕形貌等进行分析。结果表明,织构化TC4表面硬度提升约60%,其中三角形凹坑织构表面综合硬度最高;微织构能有效降低TC4表面接触过程的摩擦系数,其中圆形与矩形织构摩擦系数最低,较无织构表面减少约10%;微织构能捕获磨屑,减少磨粒磨损,提高耐磨性能,相同接触条件下,织构化试样磨损量减少了50%;当载荷一定时,速度增加可使织构化TC4表面摩擦系数降低;当摩擦速度一定时,载荷降低可导致织构化TC4表面摩擦系数降低。本研究可为提升钛合金表面摩擦学性能提供研究思路,减少钛合金因摩擦磨损造成的损失与事故。     

Effects of Adsorption of Albumin and Gamma-Globulin on the Tribological Performance of a Diamond-Like Carbon Film

The effects of surface adsorption of bovine serum albumin(BSA) and human gamma-globulin(HGG) on the tribological performance of a DLC film were investigated using a quartz crystal microbalance with dissipation(QCM-D), a ball-on-disk reciprocating tribometer, and a three-electrode electrochemical cell. The results showed that the wear depth in the BSA solution was higher than that in the HGG solution. In the HGG solution, the HGG-adsorbed layer could act as a lubricating layer and protect the DLC film from wear. The wear volume of DLC film in BSA and HGG mixture solution was higher than that in single HGG solution. This may be because the BSA molecules inhibit the formation of HGG adsorbed layer during sliding.     

气体作冷却润滑剂的绿色切削试验

为实现绿色切削,研究了无污染、无危害的冷却润滑技术.采用氮气、氧气、二氧化碳气、氩气及过热水蒸气作冷却润滑剂,进行了单因素切削试验.试验结果表明,这些气体冷却润滑剂可以减小切削变形、切削力,降低切削温度,改善加工表面形貌.根据试验结果和冷却润滑作用机理分析可知,气体在切削中具有一定的冷却润滑作用,同时具有来源广泛、无毒害和污染、不用回收处理等绿色特点,故气体具备绿色切削的潜力.