“砖-泥”结构陶瓷封严涂层横向裂纹扩展抑制机理  

Inhibition Mechanism of Transverse Crack Propagation in Ceramic Sealing Coating with"Brick-Mud"Structure

作　　者：程涛涛 吴治兵 蒋家有于 曹雨函 马梁 张莹[3] CHENG Taotao;WU Zhibing;JIANG Jiayouyu;CAO Yuhan;MA Liang;ZHANG Ying(College of Science,Civil Aviation University of China,Tianjin 300300,China;Key Laboratory of Civil Aircraft Airworthiness and Maintenance,Civil Aviation University of China,Tianjin 300300,China;College of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学理学院,天津300300 [2]中国民航大学天津市民用航空器适航与维修重点实验室,天津300300 [3]中国民航大学航空工程学院,天津300300

出　　处：《表面技术》2025年第7期212-224,共13页Surface Technology

基　　金：中央高校基本科研业务费自然科学重点项目(3122025081)。

摘　　要：目的热循环下过早的剥落失效是陶瓷基封严涂层目前面临的瓶颈问题。选取“砖-泥”结构涂层为研究对象,基于孔隙“吸引”效应,探究该涂层横向裂纹扩展抑制机理,为解决涂层易于热循环剥落失效的问题提供参考。方法采用有限元仿真计算方法,建立不同孔隙半径的“泥”层模型,分析不同“泥”层模型在热循环条件下的应力场及横向裂纹扩展行为。结果在“泥”层中引入的孔隙具有“应力再分布”功能和“应力集中”功能。含孔隙“泥”层的应力集中位置由无孔隙时的“砖”层/“泥”层界面处转移至孔隙周围,并且应力场作用区域显著缩小;与原始“泥”层相比,含孔隙“泥”层模型承受的最大拉伸应力(σ22 max)和最大剪切应力(σ12 max)显著提高。孔隙半径分别为1、2、3、4μm的“泥”层模型中横向裂纹扩展长度分别减小了84.3%、54.8%、51.5%、59.5%,能量耗散水平分别降低了98.5%、62.7%、91.1%、86.9%。当孔隙半径从0μm增至1μm时,针对横向裂纹扩展的抑制效果最为显著。结论孔隙具有“应力再分布”功能和“应力集中”功能,它在热循环过程中表现出“裂纹吸引”效应,从而改变了裂纹的扩展方向,并且抑制了裂纹的连续扩展。As one of the core technologies of aero-engine,ceramic high-temperature seal coating technology has been widely applied to make aerospace materials.Such coatings face a bottleneck of early spalling failure under thermal cycle conditions.The work aims to take"brick-mud"structured coating as the research object and explore the effect of pore size on the thermal cycle performance of ceramic"brick-mud"structured seal coatings based on the pore"suction"effect,so as to optimize the microstructure of the coating and provide a reference for solving early spalling failure.Finite Element Simulation is used to establish"mud"layer models with different pore radii(0,1,2,3,4μm).The stress field and transverse crack propagation behavior of the"mud"layer models with different pore sizes under thermal cycle conditions are analyzed.The introduction of pores in the"mud'layer has the functions of"stress redistribution"and"stress concentration".The stress concentration position in the"mud"layer with pores shifts from the"brick-mud"interface in the pore-free state to the vicinity of the pores.Additionally,the stress field action area significantly decreases.Compared with the original"mud"layer,the maximum tensile stress(σ22 max)and the maximum shear stress(σ12 max)of the"mud"layer model with pores significantly increase.Meanwhile,the transverse crack propagation length in the"mud"layer models with pore radii of 1,2,3,and 4μm decreases by 84.3%,54.8%,51.5%,and 59.5%,respectively.At the same time,the energy dissipation level decreases by 98.5%,62.7%,91.1%,and 86.9%,respectively.When the pore radius increases from 0μm to 1μm,the reduction in transverse crack length is the most significant.Similarly,the reduction in energy dissipation is also the most significant.Because of the"stress redistribution"and"stress concentration",the pores exhibit a"crack attraction"effect during thermal cycle.As a result,the crack propagation direction is changed and the continuous crack propagation is inhibited.The stress field of the"mud"layer model w

关 键 词：“砖-泥”结构 热循环失效 孔隙“吸引”效应 应力再分布 应力集中 横向裂纹扩展 

分 类 号：V261.933[航空宇航科学与技术—航空宇航制造工程]