高结合性能涂层结合强度的试验研究及有限元分析

南京航空航天大学硕士学位论文高结合性能涂层结合强度的试验研究及有限元分析姓名：程序申请学位级别：硕士专业：机械制造及其自动化指导教师：闫静;左敦稳2011-03南京航空航天大学硕士学位论文I摘要在表面工程与材料科学中广泛地采用各种各样的涂层，以达到保护基体材料、满足耐热、耐磨、耐蚀等目的。如航空航天器件中的各种高温防护涂层，集成电路中绝缘涂层等。然而，涂层与基体之间的良好结合是涂层得以发挥其作用的基本条件，其结合强度的定量测试对评价涂层质量、优化制备工艺和发展新涂层技术具有非常重要的理论意义和现实意义。本文基于专利--“基于压力试验装置的高结合性能涂层结合强度测试方法及试样”，利用有限元仿真及试验验证，对专利中存在的两个问题即涂层/基体结合强度表征公式和测试试样的结构尺寸进行了深入地研究和进一步完善。主要研究内容如下：1．建立了基于专利试样的用于表征高结合性能涂层结合强度的公式；通过在涂层与基体结合界面处添加非线性弹簧单元设定单元的应力-应变本构关系参数，在应力场有限元仿真中模拟了各种涂层涂覆工艺的界面结合力，进而分析了有无金属加强板、不同锥度、结合面宽度、涂层厚度以及不同的涂层/基体材料体系对结合界面处的应力分布的影响。2．通过仿真优化，获得了优化的测试试样结构参数。为与国标试件的比对试验提供了具体的模型结构尺寸和一定的理论基础，并试验验证了优化后模型的正确性。3．采用全解耦损伤分析方法（生死单元法），模拟了涂层与基体界面开裂时的动态裂纹扩展过程，结合涂层剥落后的界面微观形貌，为更好地理解和分析在涂层失效过程中所发生的一系列复杂的断裂力学现象提供了有效手段。4．自行设计了一种可以检测力热共同作用下的涂层/基体结合强度的测试装置；对力热共同作用下的涂层/基体结合强度测试进行了试验研究，初步探索了不同热载荷和力共同作用下涂层与基体的结合性能。关键词：高结合性能，结合强度，数值模拟，应力分布，裂纹扩展，力热共同作用高结合性能涂层结合强度的试验研究及有限元分析IIAbstractInsurfaceengineeringandmaterialsscience,avarietyofcoatingstechnologyiswidelyadoptedtoachievethepurposeofprotectthesubstratematerials,tomeettheheat,wearandcorrosionandotherpurposes.Suchasaerospaceequipmentofallsortsofheat-resistanthigh-temperatureceramiccoatings,integratedcircuit’scoatingsofplayinginsulationeffect.However,thegoodcombinationbetweencoatingandsubstrateisthebasicconditionsofcoatingtoperformitsfunctions,whosequantitativetestingofbondstrengthhasveryimportanttheoreticalandpracticalsignificanceinevaluationforthequalityofcoating,optimizationforthetechnologyofcoatingpreparationandthedevelopmentofnewcoatingtechnology.Basedonthenationalpatent---“Basedonthehighcombinationperformancebondingstrengthofthepressuretestdeviceoftestingmethodsandspecimens”,thispaperanalysesandresearchesfurtherintothetwoimperfectproblemsinitbythefiniteelementsimulationandexperiments:specificcharacterizationformulaofthecoating/substratecombiningandthestructuresizesofthetestingsample.Themaincontentsareasfollows：1．Theformulaofthetestingsample’sbondingstrengthisestablishedbythemechanicsofmaterials,andinthetestingsamplestressfiniteelementsimulation,addingthenonlinearspringunitbysettingunitofstress-strainconstitutiverelationparametersbetweentheinterfaceofcoatingandsubstratecombiningtosimulatevariouscoatinginterfaceadhesionstrengthofcoating-process,andanalyzesonwhethermetalreinforcingplate,differenttaper,jointsurfacewidth,thicknessanddifferentcoating/substratematerialsystemforinfluenceofthestressdistributionbetweenthecombininginterface.2．Thebetterstructuralparametersofthetestspecimenwasaccessedtobythefiniteelementoptimization.AndprovidingaconcretemodelstructuresizesandcertaintheoreticalbasisbycomparisontestingoftheGBspecimen,andtestverificationofthecorrectnessoftheoptimizedmodel.3.Adoptsthefulldecouplingdamageanalysismethod(thedeathelementmethod)tonumericalsimulatefordynamiccrackpropagationbetweentheinterfaceofcoatingandsubstratewhenitiscracking,combiningtheinterfacemicrostructureaftercoatingspalling,provideseffectivemeansforbetterunderstandingandanalysisincoatingfailureprocessofwhathappenedinacomplexsetoffracturemechanicsphenomena.4．Throughasetcoating/substratecombiningstrengthtestdevicewhichunderthecombiningactionofforce-hotwasdevelopedindependently,forthecoating/substratecombinedstrengthtestingwhichunderthecombiningactionofforce-hotwasstudied,thecoatingandsubstratecombinationofperformanceisexploredintheconditionofthedifferentthermalloadingandforcecommonfunction.KeyWords:Highcombiningperformance,Bondingstrength,Numericalsimulation,Stressdistribution,Crackpropagation,Combiningactionofforce-hot南京航空航天大学硕士学位论文V图表清单图1.1基体喷涂涂层示意图..................................................................................................2图1.2国标拉伸法测量界面结合强度示意图.......................................................................3图1.3剪切法测量界面结合强度示意图...............................................................................3图1.4悬臂梁弯曲法测量界面结合强度示意图...................................................................4图1.5划痕法测量界面结合强度示意图...............................................................................4图2.1涂层结合强度测量方法示意图..................................................................................7图2.21/2试样受力分析示意图............................................................................................9图2.3基于压力试验装置的高结合性能结合强度测试试样几何模型示意图.................10图2.4模拟界面结合力的非线性弹簧的本构关系.............................................................11图2.5粘附单元法向的归一化本构关系.............................................................................11图2.6粘附单元切向的归一化本构关系.............................................................................11图2.7法向弹簧改进后的本构关系....................................................................................12图2.8有限元模型加载示意图............................................................................................13图2.9系统A交界面节点的应力曲线................................................................................15图2.10锥体锥度对交界面昀大法向应力和昀大剪切应力的影响...................................15图2.11结合面宽度对交界面昀大法向应力和昀大剪切应力的影响...............................16图2.12涂层厚度对交界面昀大法向应力和昀大剪切应力的影响.......................