三体磨损状态下载荷动特性对摩擦面形貌的影响

在自行研制的环－块磨损试验装置上研究了在体磨损状态下矩形波载荷特性对摩擦面粗糙度变化的影响,结果表明：（１）随着磨程的进行摩擦面粗糙度将达到一个稳定值－平衡粗糙度Ｒｑ＾ｓ,其大小与摩擦面初始形貌无关;（２）对应于某一载荷波形占空比Хｃ,Ｒｑ＾ｓ最大,当载荷波形占空比Х小于Хｃ时,Ｒｑ＾ｓ将随Х的增加而迅速增加;当Х大于Хｃ时,Ｒｑ＾ｓ随Х的增加而减小并趋于静态载荷下的Ｒｑ＾ｓ。     

干摩擦条件下载荷动特性对摩擦面粗糙度的影响

在自行研制的环 -块磨损试验装置上研究了干摩擦状态下矩形波载荷特性对摩擦面粗糙度的影响 ,结果表明 :1随着磨程的进行 ,摩擦面粗糙度将达到一个稳定值—平衡粗糙度 ,其大小与摩擦面初始形貌无关 ;2当载荷波形占空比 φ较小时 ,平衡粗糙度 Rsq 对φ的变化敏感 ,且随 φ的增加而增加。当 φ足够大时 ,Rsq 几乎不随 φ而变化     

干摩擦状态下动载荷特性对磨损的影响

在自行研制的环一块磨损试验装置上研究了干摩擦状态下矩形波载荷特性对磨损的影响,结果表明。1)矩形波载荷和静载荷作用下试件的磨损过程一样,存在跑合期和稳定磨损期;2)矩形波载荷的占空比愈小,跑合期磨损量愈少,跑合期愈长。     

油润滑下炭黑增强丁腈橡胶的溶胀与磨损行为

选用添加不同炭黑份数的丁腈橡胶,利用挂片试验装置和往复摩擦磨损试验机,分别研究油润滑下其静态溶胀和磨损行为,探讨其在油润滑下发生磨损的临界载荷。结果表明:随着炭黑份数的增加,丁腈橡胶的硬度、抗拉强度和润湿角增加,溶胀质量变化率降低,相同试验条件下橡胶试样的摩擦因数和磨损量均降低;载荷较低时橡胶不发生磨损,当载荷增大到临界值时橡胶才发生磨损且磨损量随载荷增加而增加;随着炭黑份数的增加,橡胶试样发生磨损的临界载荷也增大。     

人牙釉质纳米尺度下的摩擦磨损行为研究

利用纳米划痕仪研究了人牙釉质在纳米尺度下的摩擦磨损行为,考察了法向载荷对牙釉质摩擦磨损性能的影响。结果表明:随着法向载荷增大,人牙釉质的摩擦因数和磨损深度呈现非线性增大;载荷较小时(20mN),摩擦因数随载荷增加而快速增大,划痕表面主要呈现轻微凹陷,损伤以弹塑性变形为主;当载荷较大时(20mN),摩擦因数随载荷增加而缓慢增大,划痕表面开始出现磨屑,磨损以脆性剥层为主。     

周期性冲击射流流动对传热特性的影响分析

采用经过实验验证的数值模型研究了周期性射流冲击下的流场对传热强化的影响。根据不同波形（正弦波、三角形波和矩形波）规律变化的射流对平板的冲击会产生不同的传热特性,研究得到了滞止点处的温度、传热系数和湍流强度随时间变化的规律。研究结果表明：当正弦波射流、三角形波射流的信号处于上升阶段时,湍流强度在稍有延迟后会产生一个瞬时的增强,可对强化传热起到促进作用,但在它们随后的波形变化中湍流强度仅有缓慢的升降,矩形波射流在信号发生阶跃变化时,会产生湍流强度的脉冲增强,尤其是在信号跃降时产生的瞬时脉冲增强比信号跃升时产生的脉冲增强更大,可有效强化传热;远离滞止点的流场的周期性波动仍然存在,但幅值大大减小,矩形波射流的平均速度大于其他波形射流的速度。     

国外专利

刀具寿命检测装置[特开昭50-110171] 此发明是通过检测驱动电机负荷随刀具磨损而增加的现象来判断刀具寿命的装置。负荷的检测是根据研究电压与电流的相位差的变化而进行的。 图1中,电机1的电压和电流由各自的检测电路2和3检测,所得的检测信号通过各自的滤波电路4和8去除干扰部分,两者的输出端如图2a、e所示。在轻负荷时为互成90相位差的波形。然后把这两个波形输入到各自的知形波发生电路5和9中。 矩形波发生电路的输出(图 2 b、 f)被输入到下一级微分电路6和10。微分电路对输入的矩形波进行微分、整流,只留下正的波形输入到各自的单稳多谐…     

微动疲劳参数对钢丝微动疲劳磨损演化的影响*

微动疲劳易引起钢丝表面磨损和横截面积损失,进而造成钢丝断裂失效并缩短钢丝绳使用寿命。不同微动疲劳参数（接触载荷、疲劳载荷、钢丝直径和交叉角度）引起差异的钢丝微动疲劳磨损特性,故研究微动疲劳参数对钢丝微动疲劳磨损演化规律影响至关重要。基于摩擦学理论和Marc仿真软件构建钢丝微动疲劳磨损模型,探究接触载荷、疲劳载荷、交叉角度和钢丝直径对钢丝微动疲劳磨损演化的影响规律。结果表明：钢丝微动疲劳磨损体积主要与接触载荷和疲劳载荷有关;疲劳钢丝的磨损深度、磨损率及磨损体积随着接触载荷的增加而增大,且不同接触载荷下疲劳钢丝磨损体积均随着循环次数的增加而呈线性增加;随疲劳载荷幅值的增加,疲劳钢丝的磨损深度、磨损率及磨损体积均呈增加趋势;在不同疲劳载荷范围下疲劳钢丝的磨损体积均随着循环次数的增加而呈线性增加;当接触载荷、疲劳载荷及钢丝间摩擦因数相同时,不同交叉角度和不同加载钢丝直径下疲劳钢丝的磨损体积相同。     

基于SOPC与DDS技术的函数信号发生器

提出一种利用SOPC (System on a Programmable Chip)技术及DDS技术开发信号发生器的方法,只需用一片FPGA芯片加必要的外围电路就可以实现函数信号发生器的功能.所设计的信号发生器可以输出正弦波、三角波、矩形波3种波形,且矩形波的占空比可调.每种输出波形的频率最小值为1 Hz,最小步进值为1 Hz.     

浸金属碳滑板/铜银合金接触线载流摩擦磨损性能的试验研究

选取地铁刚性接触网中现役的浸金属碳滑板与铜银合金接触线为接触副,模拟地铁弓网的实际运行状况,在环-块式试验机上研究直流电流为200~400 A、法向载荷为15~40 N、滑动速度为40~120 km/h工况下浸金属碳滑板载流摩擦磨损性能。结果表明：摩擦因数随电流和滑动速度的增大而减小,随法向载荷的增大而增大;磨损量随电流和滑动速度的增大而增大,当电流较小时（如200 A）,磨损量和法向载荷之间存在一个阈值,当电流较大时（如400 A）,磨损量随法向载荷的增大而减小;滑板温度随电流的增大而增大,随法向载荷增大而减小,当电流较小时（如200 A）,滑板温度随速度的增大而增大,当电流较大时（如400 A）,滑板温度随速度的增大而减小;当电流为200~300 A时,其磨损机制主要为机械磨损,当电流为300~400 A时,其磨损机制主要为氧化磨损和电弧烧蚀。     

聚甲醛等塑料的耐磨性能分析

分析了塑料耐磨性能的影响因素，比较了聚甲醛等塑料在不同载荷及不同对磨时间下的磨损情况。     

磨损自补偿的载荷效应研究

通过载荷对磨损自补偿添加剂的性能的影响研究,发现在磨损自补偿添加剂ＳＷ４的作用下,钢－铜摩擦副的磨损量与载荷无关;而且载荷越大,钢－铜摩擦副的磨损自补偿效应越显著,这些结果不同于传统的摩擦学理论。因此。磨损自补偿添加剂ＳＷ４特别适合于重载工况下运行的钢－铜摩擦副,如轧钢厂压下系统的丝杆－螺母副,为提高这类重载钢－铜摩擦副的寿命和可靠性提供了一条有效途径。     

Fretting of Hardened Steel in Oil

To determine the effect of hardness on fretting wear, tests of AISI 4340 steel were made in an oil bath using a new machine designed to make fretting corrosion tests with a wide range of parameters. Hardness values from 258 to 743 Vickers were tested, the hardest specimen having a nitrided surface. The fretting action used, 0.005 in. reciprocating motion at pressures from 430 psi to 5840 psi, produced much less fretting than similar tests in air, with little or no oxide products resulting. The galled areas were measured for depth of pit and height of deposit with the results indicating some small effects due to hardness up to 460 Vickers. The nitrided specimens, however, produced smaller fretted areas and the roughening of their surfaces was shallow.     

Wear Characteristics of Large Grinding Balls in an SAG Mill

The wear characteristics of larger than 120 mm-diameter grinding balls used in large semiautogenous (SAG) mills is studied in the present paper. SEM observation on the worn ball surface reveals a severe microcutting process. Abrasion grooves can be found on the overall surface. Moreover, persistent microcracks are found on the surface. The observation on the cross section indicates extended white layers and white bands exist in the subsurface of worn balls. The white layer is not homogenous on the surface. The largest white layer is about 20 μm thick and 1.3 mm long. The wear resistance of the white layer is tested with a simulated high stress impact wear tester. It is found that the white layer is associated with delamination wear, which significantly increases the wear rate. The delamination wear mechanism is explained from the intensely deformed microstructure and microcracks inside the white layer. Based on the experimental results, a wear formula consisting of both microcutting wear and delamination wear is submitted. This formula means that high wear resistance is only achieved when the hardness and fracture toughness of grinding balls are increased simultaneously.     

Ekonol/G/MoS_2/PEEK复合材料的磨损机理研究

用模压方法制备了Ekonol/G/MoS2 /PEEK复合材料 ,通过摩擦磨损实验方法对材料的耐磨性能进行了研究 ,并用SEM对磨损表面进行了观察和分析 ,在此基础上探讨了复合材料的磨损机理。结果表明 :与PEEK相比 ,复合材料具有优良的耐磨性能 ;随着Ekonol含量的增加 ,复合材料的磨损机理发生了由粘着磨损向疲劳磨损的转变     

凸轮机构磨损数值仿真软件研制

根据零件磨损过程一般数值仿真方法 ,以凸轮机构为研究对象 ,开发出不同类型凸轮磨损仿真软件 ,可实现不同极根条件下的凸轮磨损寿命预测、参数优化和状态监测等功能。     

Wear Behavior of Aluminum Alloys at Slow Sliding Speeds

The investigated slow sliding speeds presented in this work enable the understanding of the wear behavior on aluminum alloys and could possibly facilitate the completion of the previously proposed wear mechanism map for aluminum at this slow sliding speed range. Dry sliding block-on-ring wear tests were carried out on aluminum alloys, AA5754 (Al-Mg), AA6082 (Al-Mg-Si), and AA7075 (Al-Zn-Cu), at a very slow sliding speed range (<0.01 m/s). A bearing steel ring of AISI 52100 was used as the counterbody. Tests were performed at varying contact pressures, 20, 100, and 140 MPa, and sliding speeds ranging from 0.001 to 1.5 m/s. The wear tracks and debris collected were examined by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD), with the aim of analyzing their morphology and composition. At relatively slow sliding speeds (>0.01 m/s), the specimens exhibited a wear process placed at the mild wear regime, characterized by oxidation and delamination mechanisms of both the aluminum specimen and the steel ring. However, at very slow speed range (<0.01 m/s), an increase in the wear rate and the friction coefficient is observed for all of the aluminum alloys, thus suggesting that an alternative wear mechanism could be taking place.     

计算直齿圆柱齿轮传动磨损寿命的新方法

导出了直齿圆柱齿轮传动磨损量的解析算式；提出了确定直齿圆柱齿轮传动许用磨损量的一种新方法；并得出了直齿圆柱齿轮传动磨损寿命的计算公式和校核公式     

汽车轮胎磨损机理的研究

综合分析了汽车轮胎和路面间相互作用产生的磨损形式和磨损机理,以及研究轮胎磨损常采用的方法。运用摩擦学原理提出了轮胎磨损的分类形式,为正确预测正常工作条件下的轮胎磨损率提供了必要的基础知识。     

Characterization of mar/scratch resistance of coatings with a Nano-indenter and a scanning probe microscope

Mar/scratch resistance characterization techniques are presented in this paper, in which a Nano-indenter and a scanning probe microscope (SPM) are used to measure the micro mar resistance (MMR), different responses of coatings to the marring stress, and critical forces for rough trough, cracking, delamination, and chipping, quantitatively. It provides a full spectrum of the mar/scratch resistance behavior of the tested samples. To comprehensively evaluate a coating/material in a specified application, introduction of a quantitative index is very useful. The concept of the index and the procedure to calculate it are described in the paper, too. In addition, to meet the variety of coatings/materials properties and the requirements in their applications, some complementary test methods are discussed.