MoDTC增强型磁性液体减摩性能试验研究

为提高磁性液体的减摩性能,在现有Fe3O4磁性液体的基础上,通过微量添加二烷基二硫代氨基甲酸钼（MoDTC）,制备一种MoDTC增强型磁性液体。对MoDTC增强型磁性液体微观粒子的结构、组成成分、磁性能进行测试分析,在不同载荷、速度条件下进行摩擦磨损试验,探究MoDTC含量对磁性液体摩擦磨损性能的影响。实验结果表明：MoDTC增强型磁性液体比铁磁性液体饱和磁化强度小,且剩磁几乎为0,具有较好的磁性能;在试验研究范围内,Fe3O4磁性液体润滑下的摩擦因数比油润滑低,MoDTC增强型磁性液体的摩擦因数低于Fe3O4磁性液体的摩擦因数,且MoDTC质量分数为6%时减摩效果较佳;当载荷在25~45 N范围内,MoDTC增强型磁性液体的摩擦因数先随载荷增大而减小,超过临界值30 N后,摩擦因数随载荷增大而增大。研究结果表明,磁性液体中加入适量的MoDTC具有较好的减摩性能,能在一定程度上改善磁性液体的润滑性能。     

磁性液体中纳米颗粒分散稳定性及外加磁场下的摩擦学性能研究

为研究磁性液体在磁场中的润滑性能,将制备的油酸修饰的纳米Fe3O4磁性颗粒分散于聚α-烯烃合成油中,制备了含纳米Fe3O4的聚α-烯烃合成油基磁性液体;在高速离心机上考察了磁性液体的分散稳定性,在改造的环块摩擦磨损试验机上评价了不同外加磁场强度下的磁性液体抗磨减摩性能.结果表明:所制备的磁性液体分散稳定;外加磁场提高了磁性液体的抗磨减摩性能,随着外加磁场强度的增加,磁性液体的抗磨减摩性能明显提高.     

磁性液体性能显示装置设计

针对目前磁性液体性能演示装置的缺点，设计了新的性能显示装置。通过电磁铁的往复运动改变它与磁性液体之间的距离，从而使磁性液体的表面出现周期性的变化。     

多孔UHMWPE的制备与摩擦学性能研究

用热压成型法制备多孔超高分子量聚乙烯(UHMWPE)和普通UHMWPE试样,在改制的摩擦磨损试验机上考察2种试样在水润滑和牛血清润滑下的摩擦磨损性能。结果表明:普通UHMWPE均处于边界润滑区域;多孔UH-MWPE在较低载荷下因可以获得额外的润滑而形成混合润滑,摩擦因数和磨损量较低,其磨损机制为轻微的擦伤磨损;随着载荷的增加,多孔UHMWPE试样的磨损量明显上升并高于同等条件下普通UHMWPE,呈现较严重的切削磨损;多孔UHMWPE只适合应用于低载工况下。     

CrN活塞环涂层的摩擦学性能

以PVD方法在不锈钢渗氮活塞环基体上沉积了厚约30μm的CrN涂层。采用2种GF-3等级的全配方发动机油作为润滑剂，在SRV试验机上，对比了具有／没有CrN涂层的不锈钢渗氮活塞环的摩擦学性能。试验结果表明，CrN涂层能使摩擦因数数较快的稳定且数值较低，同时活塞环及其对磨缸套的磨损量也大大降低，对磨缸套的磨损量减少了80％以上。SEM分析结果表明，由于CrN涂层具有较高的硬度和较低的表面粗糙度，可以降低磨粒磨损，且能使对磨的缸套试样较快地与之适配，从而促进了摩擦反应膜的形成和扩展，是摩擦因数和磨损量降低的主要原因。     

磁性液体研磨技术

对传统研磨方法和特点作了简介后,阐述了磁性液体研磨中使用的磁性液体功能材料、磁性液体研磨的原理和方法,以及它能达到的加工精度,例举了它的应用场合,并展示了它的最新研究动态和应用前景。     

TiNi60合金与钢球和陶瓷球配副的摩擦学性能对比分析

分别采用GCr15钢球和Si_3N_4陶瓷球与TiNi60合金盘为摩擦配副,使用CETRUMT-2摩擦磨损试验机、MM-3型金相显微镜和TR200粗糙度仪综合考察了TiNi60合金在不同载荷和频率下的摩擦因数、表面形貌、磨痕轮廊和磨损量。实验结果表明:Si_3N_4陶瓷球与TiNi60合金配副时摩擦因数小于GCr15钢球与TiNi60合金配副;Si_3N_4陶瓷球与TiNi60合金对磨过程中的犁沟作用小于GCr15钢球与TiNi60合金配副,磨痕较平滑;Si_3N_4陶瓷球与TiNi60合金对磨后磨痕深度较浅,磨痕长度较长,并且随着载荷的增加,磨痕深度和长度的增加程度均小于GCr15钢球。表明Si_3N_4陶瓷球与TiNi60合金配副的摩擦学性能优异,该摩擦配副更适合作为低速轻载轴承用于摩擦学领域。     

磁性液体及其密封应用研究综述

介绍了纳米磁性液体的特性及其应用，磁性液体在动密封方面的应用尤为重要。综述了磁性液体科学技术在国内外的研究现状及存在的问题，提出了磁性液体密封的研究方案与技术路线，指出了该领域的主要课题及创新方向。     

磁性液体粘性减阻技术

磁性液体粘性减阻技术是一种新兴的技术。介绍了磁性液体粘性减阻技术原理,并与其他减阻技术作了对比,例举了它的应用场合,并论述了它的最新研究动态和发展前景。     

不同润湿性CFR/PEEK表面在不同介质中的摩擦学性能

改变CFR/PEEK表面润湿性,利用HARKE接触角测量仪测量表面接触角,采用OLYMPUS OLS-3100奥林巴斯激光共聚焦显微镜扫描试件表面,获取真实二维照片和三维形貌图,采用MMD-5A标准摩擦磨损试验机在水、海水和液压油介质中进行摩擦磨损试验。结果表明：疏水(油)表面可以有效减小摩擦系数和磨损量,同一种润湿性试件在不同介质中的摩擦系数比较,疏水(油)表面在水介质中摩擦系数最小稳定在0.03左右,海水介质中为0.04左右,液压油介质中为0.1左右;磨损量比较,疏水(油)表面在水介质中磨损量最少为2 mg,海水介质中为7 mg,液压油介质中为1 mg;不同介质中,润湿性对摩擦系数的影响为水<海水<液压油。     

生物基汽油添加剂摩擦性能实验研究

在SRV高温摩擦磨损实验机上,在280℃高温和常温条件下,对比研究了一种市售生物基添加剂及改性后的生物蘑添加剂作为润滑剂的摩擦磨损性能。实验结果表明,原剂和改性添加剂都能够大幅度降低摩擦因数,在280℃高温条件下的摩擦因数分别由干摩擦状况下的0．5279下降为0．09414和0．107897。在常温条件下,原剂和改性添加利的摩擦因数分别为0．0858和0．098859。通过计算发现,在上止点位置附近,加入原剂和改性添加剂后摩擦功耗分别降低了82．3％和80％。相比原剂,改性后生物基添加剂提高了低温环境下的流动性能,但润滑性能有所降低。     

Tribological Behavior of Polytetrafluoroethylene under Unidirectional Rotation,Reciprocating Sliding,and Torsion Motion

The experimental friction coefficient of polytetrafluoroethylene (PTFE) increased in the order of unidirectional rotating motion (URM), reciprocating sliding motion (RSM), and face-on-face torsion motion (FTM), whereas the wear mass loss decreased. The contact zone of PTFE composites exhibited different wear mechanisms with various motions. Under URM, RSM, and FTM, the wear particles were presented as banding, long strips, and irregular floccus clumps. The higher shear force produced by more coupled nodes would result in a higher friction coefficient. The accumulated elastic hysteresis and plastic deformation in corresponding trajectories potentially enabled a better understanding of the particle morphology under URM, RSM, and FTM, respectively.     

Influence of Surface Finishing on the Tribological Behavior of Self-Lubricating Iron-Based Composites

Recently, we presented the tribological evaluation of self-lubricating sintered steels produced by taking advantage of the powder injection molding process, the recently introduced plasma-assisted debinding and sintering process, and the in situ formation of solid lubricant particles. This new processing route promotes the in situ generation of nanostructured turbostratic graphite particles during silicon carbide dissociation. In this work, we present the influence of surface finishing on the tribological behavior of self-lubricating composites sintered at 1150°C with (3 and 5 wt%) and without SiC additions. We discuss the effects of the surface topography (R_a) on the friction coefficient and wear rates of specimens and counterbodies. The tribological behavior was analyzed using linear reciprocating sliding tests (constant load of 7 N, 60-min duration). It was shown that the reduction in surface roughness increased both the friction coefficients and wear rates of specimens and counterbodies, probably due to plastic deformation and consequent graphite reservoir sealing. Chemical analyses of the wear scars using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed a tribolayer that was composed predominantly of carbon and oxygen. Analyses of the wear scars showed traces of plastic deformation on both samples and counterbodies and the predominance of abrasion as the main wear mechanism.     

纤维增强树脂基摩阻材料的摩擦学研究进展

综述了纤维增强树脂基摩阻材料的研究和发展，主要分析了树脂基体、增强纤维和填料以及温度和PV值对摩阻材料摩擦学性能的影响及作用机理，简述了摩阻材料磨损机理的研究现状和主要磨损类型。并提出了今后研究摩阻材料应重视的问题。     

Tribological properties of carbon-nanotube-reinforced copper composites

Tribological properties of carbon-nanotube-reinforced copper composites were investigated using a pin-on-disk test rig under dry conditions. The composites containing 4–16 vol% carbon nanotubes (CNTs) were fabricated by a powder-metallurgy technique. The tests were carried out at normal loads between 10 and 50 N, and the effect of volume fraction of CNTs on tribological behavior of the composites was examined. The composites revealed a low coefficient of friction compared with the copper matrix alloy. Due to the effects of the reinforcement and reduced friction, the wear rate of the composites decreased with increasing volume fraction of CNTs at low and intermediate loads. The composites with a high volume fraction of CNTs exhibited high porosity and their wear resistance decreased under high-load conditions.     

电流对铬青铜/紫铜摩擦学特性的影响

采用自制的销盘摩擦磨损试验机,在载流条件下对铬青铜QCr0.5/T2铜的摩擦学特性进行了研究,结果表明电流对摩擦因数和磨损率具有显著影响,电流越大,磨损率越高,摩擦副磨损越严重,摩擦因数越大。载流条件下,摩擦表面发生电点蚀,并出现局部熔化和雨滴状金属颗粒。     

KH-550改性钢纤维对半金属摩擦材料摩擦学性能的影响

为使半金属摩擦材料中的钢纤维组分能与基体树脂更好地融合,使用硅烷偶联剂对钢纤维组分进行表面改性,用WGH-30/6红外分光仪研究不同改性方法的改性效果,按照GB5763-98在XD-MSM定速式摩擦试验机上考察不同改性钢纤维制备的半金属摩擦材料的摩擦磨损性能,并分析摩擦磨损机制。结果表明:半金属摩擦材料中的钢纤维经过硅烷偶联剂KH-550表面改性处理后,平均摩擦因数上升10%且比较稳定,平均磨损率下降30%,在高温350℃时,磨损率下降了约47%。     

Tribological Behavior of Carbon-Nanotube-Filled PTFE Composites

Carbon nanotube/polytetrafluoroethylene (CNT/PTFE) composites with different volume fractions were prepared and their friction and wear properties were investigated using a ring-on-block under dry conditions. It was found that CNTs signifi-cantly increased the wear resistance of PTFE composites and decreased their coefficient of friction. PTFE composites with 15–20 vol.% CNTs exhibited very high wear resistance. The significant improvements in the tribological properties of CNT/PTFE composites are attributed to the super-strong mechanical properties and the very high aspect ratio of CNTs. The CNTs greatly reinforce the structure of the PTFE-based composites and thereby greatly reduce the adhesive and plough wear of CNT/PTFE composites. The CNTs are released from the composite during sliding and transferred to the interface of the friction couples. They thus serve as spacers, preventing direct contact between the mating surfaces and thereby reducing both wear rate and friction coefficient.     

镍基合金喷熔层摩擦学行为与机制的研究

采用热喷熔工艺制备了两种镍基合金喷熔层,并选用高锰钢、不锈钢作为对比材料,研究了镍基合金喷熔层的摩擦磨损性能。研究结果表明：镍基合金喷熔层具有良好的耐磨损性能和较低的摩擦系数。镍含量对喷熔层的摩擦学性能有显著影响,高镍含量的镍基合金,其耐磨性能明显优于低镍含量的镍基合金。在低速轻载条件下,镍基合金喷熔层的磨损机理为微观犁削;高速重载时,表现为粘着磨损和磨料磨损,其中高镍含量的喷熔层表面形成了致密的转移膜,有效地降低了磨损率。