（梯度）（ti，al）n涂层对不锈钢基材疲劳性能的影响

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1、沈阳理工大学硕士学位论文摘要本文采用电弧离子镀技术在飞机压气机叶片材料1Crl1Ni2W2MoV不锈钢上沉积了耐磨且抗氧化腐蚀性能良好的(梯度)(Ti，A1)N涂层，研究了室温以及高温氧化环境中(梯度)(Ti，A1)N涂层的结构、应力等对涂层一不锈钢基材系统的高周疲劳行为的影响规律及影响机理。SEM观察(梯度)(Ti，AI)N涂层的结构平整致密，XRD相分析表明(梯度)(Ti，AI)N涂层为BINaCI结构。涂层应力分布的测量采用薄膜剥层基片变形法(单面弯曲与化学剥层相结合的方法)。结果表明：(梯度)(Ti，AI)N涂层内残余应力为压应力，涂层应力从涂层／基材界面起

2、随膜厚增加而逐渐增大，在涂层中部出现压应力的最大值，然后向涂层表面方向逐渐减小。界面附近梯度(Ti，A1)N涂层的残余应力值较低，与TiN涂层的应力相近，小于Ti50A150N涂层的残余应力。TiN涂层的平均残余应力最小，(梯度)(Ti，AI)N涂层的平均应力随着涂层厚度的增加而增大。高周疲劳实验在旋转弯曲疲劳实验机上进行，做出(梯度)(Ti，AI)N涂层样品以及基材样品的S．N曲线，计算出疲劳极限并观察疲劳断口形貌。室温时，施加了Ti70A130N涂层与梯度(Ti，AI)N涂层样品的条件疲劳极限分别为571．0MPa和575．0MPa，较不锈钢基材的条件疲劳极限5

3、33．0MPa有约7％及8％的提高。5000C时，不锈钢基材，Ti70A130N涂层样品及梯度(Ti，A1)N涂层样品的条件疲劳极限分别为450MPa，494MPa，450MPa。在同一应力级下，梯度(Ti，AI)N涂层样品的平均疲劳寿命要高于不锈钢基材样品。基材内部的固有缺陷(夹杂等)是疲劳裂纹萌生的源头。涂层的旌加提高不锈钢基材疲劳寿命的原因主要在于梯度(Ti，A1)N与Ti70A130N涂层中的残余压应力作为滑移变形的阻力可阻碍疲劳裂纹的萌生和扩展。关键词：(梯度)(Ti，A1)N涂层；电弧离子镀；残余应力；疲劳沈阳理工大学硕士学位论文Abstract(Gra

4、ded)(Ti，A1)Ncoatingswithexcellentwearresistanceandextremeoxidationandcorrosionpropertiesweredepositedon1Crl1Ni2W2MoVstainlesssteelbyarcionplating．Theinfluencesofstructuresandresidualstressesofthe(graded)(Ti，AI)Ncoatingsonthefatiguepropertiesofthebulkmaterialinroomandhightemperaturewere

5、studiedandthemechanismswerediscussed．．The(graded)(Ti，A1)NcoatingswereflatandcompactobservedbySEM，withB1NaClstructureidentifiedbyXRD．Thedepthdistributionsoftheresidualstressesin(graded)(Ti，A1)NcoatingsdepositedonthesteelweremeasuredbytheStrippingLayerSubstrateCurvatureTechnique．Theresul

6、tsshowthattheresidualstressesinthecoatingswerecompressive，whichincreasedgraduallyfromthecoating／substrateinterfaceandreachamaximumvalueatthemiddleregion，thendecreaseduntilthesurface．Theresidualstresslevelinthegraded(Ti，AI)NneartheinterfacewassimilartothatofTiNandmuchlowerthanthatinTiso

7、AlsoN．FurthermoretheaveragestressinTiNwasthelowest，andtheaveragestressinthegraded(Ti，AI)NcoatingwaslargerwhenthefilmWasthickenRotarybendingfatiguetestwasadoptedforpredictinghigh—cyclesfatiguepropertiesofthe(graded)(Ti，A1)Ncoatedandbulksteel．TheS—Ncurvesandthefatiguelimitsweretested，a