采用硅橡胶、丁腈橡胶共混改性酚醛树脂黏结剂,利用湿法工艺制备纸基摩擦材料试样。借助湿式摩擦性能试验机以及扫描电镜研究橡胶改性酚醛树脂黏结剂对纸基摩擦材料摩擦磨损性能和表面形貌的影响。实验结果表明:与单纯采用酚醛树脂黏结剂相比,使用丁腈橡胶-酚醛树脂共混黏结剂提高了纸基摩擦材料的静摩擦因数,但动摩擦因数和耐磨性能有所降低;而使用硅橡胶-酚醛树脂共混黏结剂不仅提高了纸基摩擦材料的动、静摩擦因数,也使其耐磨性能有所提升。

The paper-based friction materials were fabricated by impregnated the phenolic resin adhesive modified by ni-trile butadiene rubber and silicon rubber.The tribological properties of the paper-based friction material were investigated on a wet friction tester and the surface morphologies were analyzed using a scanning electron microscope.Experiment re-sults show that,compared with the phenolic resin adhesive,the blending adhesives of phenolic resin and nitrile butadiene rubber can improve the static friction coefficient of paper-based friction materials,but the dynamic friction coefficient and abrasion performance of the friction materials are declined.However,the blending adhesives of phenolic resin and silicon rubber can enhance tribological properties of paper-based friction materials and improve its abrasion performance.

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．

A series of sliding‐rolling friction and wear experiments of a GCr15 steel ball against GCr15 steel plate under lubricated conditions were performed on NGY‐6 nano‐film thickness measuring instru‐ment .The effects of contact stress ,speed of steel ball and sliding‐rolling ratio on the friction coefficient and morphologies were investigated .The results showed that the friction coefficient increased with the increas‐ing of sliding‐rolling ratio ,and then reached a steady state at a fixed contact stress and speed of steel ball . As the sliding‐rolling ratio was fixed ,the friction coefficient increased gradually with the increasing of con‐tact stress .On the condition that the ball speed was lower than 300 r/min ,the friction coefficient decreased with the increasing of steel ball speed .When the steel ball speed and contact stress were over 300 r/min and 0 .84 GPa respectively ,the friction coefficient increased as the ball speed increased .Stribeck curve indi‐cated t

采用造纸工艺制备了一种湿式纸基摩擦材料，研究了硫化温度对材料耐热性、动摩擦因数、摩擦力矩、磨损率、磨损表面微观形貌的影响。研究结果表明：硫化温度高于或低于160℃时，材料的耐热性能减弱，树脂和竹纤维的热分解较为严重，热磨损主要影响着材料摩擦磨损性能的稳定；160℃时，材料的磨损较小，磨损表面平整致密，在循环制动中动摩擦系数波动性较小，摩擦力矩的变化较平稳，降低了制动的噪音。

Wet paper-based friction material was prepared through the paper-making process , and the influences of curing temperature on the friction materials ,including heat resistance , dynamic friction coefficient ,friction torque ,wear rate and micro morphology of the worn sur-face were studied .The results show that the heat resistance of friction material were weak-en ,and thermal decomposition of resin and bamboo fiber became serious w hen the curing temperature is higher or lower than 160 ℃ ;the thermal worn mainly affect the stability of tribological performance of friction material .At the curing temperature of 160 ℃ ,the worn rate of friction material with flat and compact worn surface is minimum ,and dynamic friction coefficient and friction torque keep relatively stable ,which reduce brake noise .

采用双靶磁控溅射方法,在合适的溅射参数下在40Cr钢基体上制备巴氏合金薄膜,并对其结构以及摩擦学性能进行分析。结果表明:薄膜中出现Sn,SbSn,Cu6Sn5多种物相,其纳米硬度为5.7 GPa,弹性模量为235 GPa,具有较高的弹性模量硬度比;油润滑时在合适的载荷和转速下巴氏合金薄膜和对磨件之间会形成动压油膜,从而降低摩擦磨损,其中在0.3 N载荷、150 r/min转速下摩擦因数可低至0.05;巴氏合金薄膜不适合用于干摩擦。

Babbit alloy film was prepared on 40Cr steel base by double targets magnetron sputtering method with appropri-ate sputtering parameters,and its structure and tribological properties were analyzed.The results show that Sn,SbSn, Cu6 Sn5 and other phases appear in the babbit alloy film.The film has a high ratio of elastic modulus to hardness,its nano hardness is 5.7 GPa,elastic modulus is 235 GPa.Under oil lubrication and a suitable load and speed,the dynamic pressure oil film appears between babbit alloy film and friction part,so as to reduce the friction and wear.A low friction coefficient of 0.05 is got in the load of 0.3 N and speed of 150 r/min.Babbit alloy films are not suitable to work in dry friction.

轮对的压装质量与其性能有着直接的关系。传统的轮对压装多是依据经验来进行轮轴的选配,没有明确的参考标准,因而导致压装合格率较低。文章以CRH3型动车组轮对为例,利用Ansys软件建立了二维轴对称模型对轮对压装过程进行模拟仿真,通过非线性接触分析得出过盈量、摩擦因数、公差等因素对轮对压装应力分布及压装曲线的影响。结果表明,过盈量对轮对应力及压装曲线均有较大的影响;摩擦因数对应力值影响较小,对压装曲线则影响较大;公差对轮对应力影响比较明显,对压装曲线的影响则比较微弱。最后在满足国家标准要求的前提下给出一个范围,以此作为轮对压装的参考标准,可提高轮对压装的质量,保证机车安全平稳运行。

The press-fitting quality of the wheelset is closely related to its performance.For traditional wheelset press-fitting,wheels and axles are mainly matched based on experience without explicit reference standards,so the press-fitting conforming rate is low.The paper introduces the 2D axial symmetry model built by Ansys for simulation of the wheelset press-fitting process with the wheelset of CRH3 motor train as an example.The effect of interference magnitude,friction factor,tolerance and other factors on the press-fitting stress distribution and curve of the wheelset is worked out through non-linear contact analysis.The result shows that interference magnitude has great effect on the wheelset stress and press-fitting curve;the friction factor has small effect on the stress value but great effect on the press-fitting curve;tolerance has clear effect on the wheelset stress but weak effect on the press-fitting curve.Under the premise of meeting national stand-ards,the range is provided bas