【作者】 李鹏；

【导师】 李健； 张永振；

【作者基本信息】 机械科学研究总院 ， 机械设计及理论， 2007， 博士

【摘要】 以国家自然科学基金重点项目(西部特殊环境下材料损伤与防护研究50432020)和国家“973”课目(强氧化环境下材料的磨损机制2007CB607603)为依托，基于摩擦学特性不是材料所固有的特性而是系统的特性的原理，针对现有的低电流、低载荷和低滑动速度的摩擦学试验机及其在此基础上获得的摩擦学规律和结论，已经不能满足目前和将来铁路机车提速的需要的现状，为此对高速铁路滑板材料载流摩擦学特性的试验设备与滑板材料载流摩擦学性能开展系统深入的研究。本论文开展的主要研究内容和所取得的成果如下：1、首次开发了大电流、高速度和重载荷的载流摩擦磨损专用试验机，能够稳定提供恒定交流电流密度2.5 A／mm~2，相对滑动速度100 m／s(12000 r／min)，载荷可达500 N(3.2MPa)，脉动冲击载荷可达20 N，为研究提速接触网和滑板的高速载流摩擦学特性及其机理，以及开发新型高耐磨性、高载流性能滑板材料提供了先进可靠的试验手段(该机已获得一项实用新型专利，ZL 2006 2 0096036.5)。2、对铜基粉末冶金材料和浸金属碳材料的使用参数进行了试验研究，结果表明铜基粉末冶金材料的最佳使用参数为电流0.45 A／mm~2、载荷0.37 MPa、滑动速度40 m／s，而浸金属碳材料的最佳使用参数为电流0.45 A／mm~2、载荷0.37 MPa、滑动速度50 m／s，在此参数下，材料的耐磨性最好。这与现阶段使用铜基粉末冶金滑板和浸金属碳滑板的电力机车的最佳运行参数完全一致，这表明：铁路系统对这两种滑板材料选择的使用参数是非常正确的；同时也表明，所研制的载流高速摩擦磨损试验机具有很好的模拟性，能够满足今后研究、开发新型高耐磨性滑板材料及其配副导线材料，研究配副使用参数的优化，载流摩擦学过程和作用机理等问题的需要。3、对铜基粉末冶金材料和浸金属碳材料的耐磨性、减摩性、回路电流相对稳定性和摩擦系数相对稳定性及其影响参数进行了较系统的研究。结果表明：(1)铜基粉末冶金材料与QCr0.5配副时，电流不能超过0.45 A／mm~2，载荷不能超过0.45 MPa，滑动速度不能超过40～50 m／s，(其中电流0.3 A／mm~2，载荷0.37 MPa下，滑动速度不能超过50 m／s；电流0.45 A／mm~2，载荷0.37 MPa下，滑动速度不能超过40 m／s)否则磨损会急剧增大。(2)浸金属碳材料与QCr0.5配副时，电流不能超过0.45 A／mm~2，载荷不能超过0.55MPa，滑动速度不能超过50 m／s，(其中电流0.37 A／mm~2，载荷0.37 MPa下，滑动速度可以达到40 m／s；电流0.45 A／mm~2，载荷0.37 MPa下，滑动速度不能超过50 m／s；电流0.6A／mm~2，载荷0.37 MPa下，滑动速度不能超过40 m／s)否则磨损会迅速增大。(3)浸金属碳材料的耐磨性显著优于铜基粉末冶金材料的，其磨损率比铜基粉末冶金材料的磨损率降低了54.8％—79.8％；其次，浸金属碳材料的载流稳定性也优于铜基粉末冶金材料的。(4)浸金属碳材料的减摩性不如铜基粉末冶金材料的，其摩擦系数比铜基粉末冶金材料的摩擦系数大，其值分别大了14.4％—150％；同时，浸金属碳材料的摩擦稳定性也不如铜基粉末冶金材料的。4、研究过程中发现，载流摩擦过程比传统摩擦过程受系统参数的影响更复杂，参数对摩擦副摩擦性能的影响规律也不完全相同，如摩擦系数波动较大，为此首次提出、并考察了载流摩擦过程中的摩擦系数的稳定性、回路电流的稳定性，以评价载流摩擦过程中材料的特性。更多还原

【Abstract】 Supported by the National Natural Science Foundation of China (No. 50432020) and theNational 973 project (2007CB607603) and due to the systematic characteristics of tribo-electficfriction pairs, great needs for researches on tribo-electric behaviors of materials of pantographstrips are becoming more and more urgently with the development of running speed and loadingelectric current of locomotives. Based on the materials used for locomotives electric supplysystem of high speed railway, the researches are carded out on following aspects in this paper.1, the special tribo-electdc tester with high sliding speed and electric current was developed,which mail working parameters are, current density up to 2.5 A/mm~2, the sliding speed 100 m/s,the load over 500 N (3.2 MPa) and the pulsant strike pressure within 20 N. This testersuccessfully simulates the tribological and electric properties of strip materials.2, By using the above tester, study on tdbological properties and carrying currentperformances of copper-base powder metallurgy material and metal impregnation carbonmaterial are carded out. The results show that the copper-base powder metallurgy materialsposses the best wear resistance under the condition of 0.45 A/mm~2, 0.37 MPa and 40 m/s and themetal impregnation carbon materials show the best wear resistance under the condition of 0.45A/mm~2, 0.37 MPa and 50 m/s which are both accordance with the running conditions of trainswhich use copper-base powder metallurgy strip and metal impregnation carbon strip.3, After systematical researches on wear resistance, reducing friction, stabilities of carryingcurrent and friction coefficient of copper-base powder metallurgy material and metalimpregnation carbon material, the following conclusions are obtained:(1), the copper-base powder metallurgy material coupled with QCr 0.5 can only be used underconditions of current less than 0.45 A/mm~2, pressure under 0.45 MPa and sliding speed less than40-60 m/s for the aim of low wear rate. The conditions in detail are that sliding speed is less 60m/s when current is 0.3 A/mm~2 and pressure is 0.37 MPa, sliding speed is less 40 m/s whencurrent is 0.45 A/mm~2 and pressure is 0.37 MPa. (2), the metal impregnation carbon material only can be used under conditions of current lessthan 0.45 A/mm~2, pressure under 0.55 MPa and sliding speed less than 50 m/s for the aim of lowwear rate. The conditions in detail are that sliding speed can reach 70 m/s when current is 0.3A/mm~2 and pressure is 0.37 MPa, sliding speed can reach 50 m/s when current is 0.45 A/mm~2and pressure is 0.37 MPa, sliding speed can reach 40 m/s when current is 0.6 A/mm~2 andpressure is 0.37 MPa.(3), wear rate of metal impregnation carbon material is lower than that of copper-base powdermetallurgy material by 54.8%-79.8% which indicates that wear resistance of former is muchbetter than that of the latter. The stability of carrying current of metal impregnation carbonmaterial is better than that of metallurgy material.(4), friction coefficient of metal impregnation carbon material is higher than that of copper-basepowder metallurgy material by 14.4%-150% which indicates that anti-friction property offormer is worse than that of latter. The stability of sliding contact of metal impregnation carbonmaterial is worse than that of copper-base powder metallurgy material.4, Due to the fact that effects of tribological parameters on the process of wear with current aremore complicated than those of common sliding process, parameters of stabilities of carryingcurrent and friction coefficient are introduced in this paper to evaluate properties of couple withcurrent.更多还原