{"title":"Thermo-mechanical and Isothermal Fatigue of a Coated Columnar-Grained Directionally Solidified Nickel-Base Superalloy","authors":"R. Kowalewski, H. Mughrabi","doi":"10.1520/STP15250S","DOIUrl":null,"url":null,"abstract":"The isothermal low-cycle fatigue (LCF) and the out-of-phase thermomechanical fatigue (TMF) behaviours of the directionally solidified nickel-base superalloy DS CM 247 LC, coated with a plasma-sprayed NiCrAlY-coating (PCA-1), were studied in detail. The investigations were performed on the uncoated, the coated substrate material and also on the pure coating material, in contrast to most existing work. The results of the isothermal LCF tests show that the fatigue life of the substrate/coating-composite is governed by the fatigue behaviour of the bulk coating material. The out-of-phase TMF cyclic deformation behaviour of the substrate/coating-composite reflects that of the components and is well described by an isostrain composite model. When the mechanical strain amplitudes experienced by the coating material are plotted against the fatigue life, the data on the coated material in isothermal LCF tests at the upper and lower temperatures of the TMF cycle, respectively, and in the TMF tests coincide. This gives further evidence that the behaviour of the coating materials governs that of the coated composite.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"16 1","pages":"3-17"},"PeriodicalIF":0.0000,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"10","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ASTM special technical publications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1520/STP15250S","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 10
Abstract
The isothermal low-cycle fatigue (LCF) and the out-of-phase thermomechanical fatigue (TMF) behaviours of the directionally solidified nickel-base superalloy DS CM 247 LC, coated with a plasma-sprayed NiCrAlY-coating (PCA-1), were studied in detail. The investigations were performed on the uncoated, the coated substrate material and also on the pure coating material, in contrast to most existing work. The results of the isothermal LCF tests show that the fatigue life of the substrate/coating-composite is governed by the fatigue behaviour of the bulk coating material. The out-of-phase TMF cyclic deformation behaviour of the substrate/coating-composite reflects that of the components and is well described by an isostrain composite model. When the mechanical strain amplitudes experienced by the coating material are plotted against the fatigue life, the data on the coated material in isothermal LCF tests at the upper and lower temperatures of the TMF cycle, respectively, and in the TMF tests coincide. This gives further evidence that the behaviour of the coating materials governs that of the coated composite.
研究了等离子喷涂nicraly涂层(PCA-1)后定向凝固镍基高温合金DS CM 247 LC的等温低周疲劳(LCF)和非相热机械疲劳(TMF)行为。与大多数现有工作不同的是,对未涂覆的基材、涂覆的基材和纯涂层材料进行了研究。等温LCF试验结果表明,基体/涂层复合材料的疲劳寿命受本体涂层材料的疲劳行为支配。基体/涂层复合材料的非相TMF循环变形行为反映了各组分的循环变形行为,可以用等应变复合材料模型很好地描述。将涂层材料所经历的力学应变幅值与疲劳寿命进行对比,发现涂层材料在TMF循环的上、低温下的等温LCF试验数据与TMF试验数据吻合。这进一步证明了涂层材料的行为支配着涂层复合材料的行为。