第39卷第2期中南大学学报(自然科学版)Vol.39No.22008年4月J.Cent.SouthUniv.(ScienceandTechnology)Apr.2008EB-PVD热障涂层热扩散系数测试方法及其影响因素牟仁德1，宋希文2，陶春虎1，何利民1(1.北京航空材料研究院腐蚀与防护研究室，北京，100095；2.内蒙古科技大学材料与冶金学院，内蒙古包头，014010)摘要：采用激光脉冲法研究电子束物理气相沉积(EB-PVD)热障涂层热扩散系数的测定，对测定结果进行误差分析，研究试样热处理状况和遮挡层对热扩散系数的影响。结果表明：随着测试温度升高，EB-PVD热障涂层的热扩散系数先减小再增大，但在25~1200℃的测试温度范围内，变化幅度不大；在25℃时测试相对误差为4.6%，其余各温度的相对误差均小于1.5%；热扩散系数的变化与陶瓷材料的本征热导率随温度的变化以及涂层的微结构密切相关；热处理使涂层中产生了垂直于基体表面的微裂纹，部分热流通过微裂纹可直接到达涂层表面，导致热扩散系数增加；喷Au加石墨复合遮挡层的试样其热扩散系数比单一石墨遮挡层试样的低，主要是由于低发射率的Au减弱了辐射对传热的贡献。关键词：热扩散系数；热障涂层；电子束物理气相沉积；激光脉冲法中图分类号：TG174.4文献标识码：A文章编号：1672-7207(2008)02−0256−06MeasurementofthermaldiffusivityofEB-PVDthermalbarriercoatingsandinfluencefactorsMURen-de1,SONGXi-wen2,TAOChun-hu1,HELi-min1(1.DivisionofCorrosionandProtection,BeijingInstituteofAeronauticalMaterials,Beijing100095,China;2.SchoolofMaterialsandMetallurgy,InnerMongoliaUniversityofScienceandTechnology,Baotou014010,China)Abstract:Thermaldiffusivityofelectronbeam-physicalvapordeposition(EB-PVD)TBCswasmeasuredusinglaserflashmethod.Theerrorrangeswereanalyzedandtheeffectsofheattreatmentandshelterlayersonthethermaldiffusivitywereinvestigated.TheresultsshowthatthermaldiffusivityofTBCdecreasesatthebeginningandthenincreaseswiththeelevationoftestingtemperature.Buttheextentofthermaldiffusivityvariationisnotvastinthewholetestingtemperaturerangefrom25℃to1200℃.Themaximumrelativeerroris4.6%at25℃andlessthan1.5%atothertestingtemperature.ThethermaldiffusivityiscloselyrelatedwiththeintrinsicpropertieschangeofceramicwiththeincreaseoftemperatureandthemicrostructureofTBCs.Micro-cracksinheat-treatedsamples,whichareperpendiculartothesamplesurface,permittedpartoftheheatflowtodirectlyreachthesurfaceofcoatingsandfinallyresultintheincreaseofthermaldiffusivity.Thermaldiffusivityofsamplewithmulti-shelterofAuandgraphiteissmallerthanthatofsamplewithsinglegraphiteshelter.ThemainreasonforthisphenomenonisthatAuwithlowemissionrateweakenstheradiationeffectonthermalconduction.Keywords:therma