接触线用稀土微合金化高强高导cucrzr合金时效析出特性研究

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1、西安理工大学博士学住论文着载流强度的增加，RE对Cu—Cr-Zr合金耐磨性能的改善作用有所下降；SEM观察和EDS分析均表明，未加电流情况下，合金的滑动磨损形式有粘着磨损、磨粒磨损和疲劳磨损，其中疲劳磨损为其主要磨损形式，而在载流磨损条件下，合金的磨损增加了电烧蚀磨损形式；研究发现在磨损表面下的亚表层中发生了再结晶现象，同时产生一个与磨损表面相垂直的拉应力分量，该应力将促进亚表层中裂纹的形成及扩展、加速合金的磨损过程。首次在本实验条件下，建立了接触线．滑块电磨损的物理模型和数学模型。关键词：Cu—Cr-Zr(-RE)合金；时效析出；动力学；残余应力分

2、布；电磨损机理和模型本研究得到国家“863”高技术发展计划项目(2002AA331110)和河南省杰出人才基金项目(0521001200)的资助。IIAbstractTitie：AGINGPRECIPlT酊IONCHARACTERISTICS0FHIGHSTRENG-THHIGHELECTRICALCONDUCTIVllYANDTRACEALLOYEDCu-Cr-ZrALLOYCONTACTWIREMajor：MaterialsScienceName：LIUYongSignature-兰：三盟Supervisor：Prof．LIUPingSignat

3、ure：AbstractAccordingtothepropertiesofcontactwireusedmaterialsofhigh·speedelectricalrailway,an绷seriestracealloyedCu-Cr-Zr(-RE)contactwireswithhighstrengthandhighelectricalconductivityweredevelopedandmanufactured．Theagingprecipitationbehaviorofthealloyswasinvestigatedinthispaper

4、．Therelativelyelectricalresistanceratio，suchasthervalueorthe△yvaluewhichwasdefinedthechangeofthervalueastheparameters，wasusedtoestimatethekineticsofisothermal-heatingandiso-speed-heatingagingpre矗pitatedbyusingthedynamicresistancemethod．Theresultsshowedthattheincubationperiodwas

5、shortenedandtheincreasedvelocityoftheAyvaluegoneupwiththeincreasedisothermal—heatingagingtemperatures．TheAyvaluewouldberatherhigherwiththelessheatingratio，andtheagingbeginningandfinishingtemperatureswouldrisewiththerapidheatingratiointheiso—speed-heatingagingprocess．Theagingpre

6、cipitationbehaviorandthestrengthenedmechanismofthesetestedCu—Cr-Zr(-RE)alloyswerestudiedcontrastively．nehardnessandelectricalconductivityvaluesofthesolutiontreatedalloyswouldriserapidlyatthebeginningoftheagingprocess．AndthevaluesofhardnessandelectricalconductivityoftheCu-Cr-Zra

7、lloyare106HVand72．8％IACSafteragedat480℃for2h，respectively．Thecolddeformationcouldofferadvantagesfortheprecipitatedphasetonucleateanddevelop,andcouldacceleratetheprecipitatedcourseofthesolutiontreatedalloys．Aftersoluted一60％deformed-agedat480℃for1htreatment．thevaluesoftheCu-Cr-7I

8、alloywouldbeincre鹤edto154HVand83．5％IACS，respectively．W