GZO/8YSZ功能梯度热障涂层热冲击过程中裂纹的生长研究  

Crack Growth in GZO/8YSZ Functionally Graded Thermal Barrier Coatings during Thermal Shock

作　　者：刘琨 王九思 杜康平 郭小满 张蕾 何文斌 都金光 明五一[1] LIU Kun;WANG Jiusi;DU Kangping;GUO Xiaoman;ZHANG Lei;HE Wenbing;DU Jinguang;MING Wuyi(Henan Key Lab of Intelligent Manufacturing of Mechanical Equipment,Zhengzhou University of Light Industry,Zhengzhou 450000,China;School of Mechanical and Electrical Engineering,Zhengzhou University of Light Industry,Zhengzhou 450000,China;School of Mechanical and Industrial Engineering,University of Toronto,Toronto M5S2E8,Canada;School of Material Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]郑州轻工业大学河南省机械装备智能制造重点实验室,郑州450000 [2]郑州轻工业大学机电工程学院,郑州450000 [3]多伦多大学机械与工业工程学院,多伦多M5S2E8 [4]太原科技大学材料科学与工程学院,太原030024

出　　处：《表面技术》2025年第7期189-202,共14页Surface Technology

基　　金：国家自然科学基金(U2004169);河南省科技攻关项目(242102230036);河南省重大科技专项(241100220100)。

摘　　要：目的探究功能梯度热障涂层(FG-TBCs)的裂纹生长机制。方法通过用户定义材料子程序,建立梯度热障涂层结构模型,并基于响应面优化的扩展有限元法(XFEM)分析TGO/TC界面幅值、热生长氧化物(TGO)厚度和纵向裂纹倾角对裂纹扩展的影响。结果在忽略TGO层初始应力的条件下,TGO厚度与TGO/TC界面裂纹扩展长度成反比;当TGO厚度从3μm增至7μm时,径向应力下降超过300 MPa,裂纹扩展长度和损伤程度显著减小。TGO/TC界面幅值是影响裂纹扩展最关键的因素,其次为TGO厚度,纵向裂纹倾角的影响最小。裂纹扩展与界面幅值呈先减后增的抛物线关系,在界面幅值约为13.6μm时,对裂纹扩展的影响最小。裂纹扩展主要发生在首次热冲击的加热阶段,此时驱动力主要来源于显著温差引起的热应力,在后续热循环中裂纹扩展和损伤依赖于应力的累积效应。结论所建立的梯度结构建模方法为更准确分析FG-TBCs内部应力分布提供了新的选择,研究结果为长寿命热障涂层的制备提供了理论和实验支持。In the pursuit of enhancing the performance and longevity of thermal barrier coatings(TBCs)in harsh operating environments,functionally graded thermal barrier coatings(FG-TBCs)have garnered significant attention as a promising alternative to traditional design.FG-TBCs exhibit a unique ability to mitigate the detrimental interfacial effects that often plague the integration of dissimilar materials,achieving a harmonious blend of thermophysical properties across their compositional gradient.This integration not only alleviates thermal stresses,but also significantly improves the overall durability and service life of the coating system.The fundamental difference in the layer-by-layer composition of FG-TBCs leads to distinct crack propagation and failure mechanisms that are markedly different from those observed in conventional TBCs.Therefore,a meticulous investigation into the crack propagation mechanisms within FG-TBCs is imperative for the development of high-performance coatings with enhanced reliability and longevity.The present study delves into the microstructural intricacies of an 8%YSZ/Gd2Zr2O7 gradient TBC,utilizing advanced computational modeling techniques to simulate its behavior under operational conditions.By incorporating the UMAT subroutine within a finite element analysis(FEA)framework,a sophisticated model that captures the thermally and mechanically graded material properties of the top coat(TC)layer across a wide range of temperatures is constructed.This model incorporates realistic features such as porosity and lamellar structures,ensuring a high degree of fidelity in simulating the coating's response to thermal and mechanical stimuli.The model comprises four distinct layers:substrate(SUB),bond coat(BC),thermally grown oxide(TGO)layer,and ceramic top coat(TC).Each layer is meticulously defined based on its material properties and geometric dimensions,ensuring that the simulation accurately reflects the coating's actual structure and composition.To investigate the crack propagation behavior at t

关 键 词：功能梯度热障涂层 扩展有限元法 响应面方法 纵向裂纹 横向裂纹 

分 类 号：TG174.4[金属学及工艺—金属表面处理]