基于多弹性参数超声反演热障涂层孔隙形貌与宏观弹性特性关系  

Relationship Between the Pore Morphology and Macroscopic Elasticity of Thermal Barrier Coatings Inverted by Ultrasonic Echo Based on Multiple Elastic Parameters

作　　者：马志远[1] 阳纪伟 孙珞茗 林莉[1] MA Zhiyuan;YANG Jiwei;SUN Luoming;LIN Li(Nondestructive Testing&Evaluation Laboratory,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学无损检测研究所,大连116024

出　　处：《中国表面工程》2025年第1期118-126,共9页China Surface Engineering

基　　金：国家自然科学基金(52175496,52075078,U22B2068)。

摘　　要：热障涂层(TBCs)内部微观结构对其宏观弹性影响显著,探究TBCs孔隙微观结构特征与宏观弹性之间的关系对于优化制备工艺参数及预测使役寿命至关重要。针对现有基于椭圆近似研究TBCs孔隙率、尺寸、取向与涂层宏观弹性关系,未考虑孔隙不规则形貌对宏观弹性影响的问题,开展了基于水浸超声背反射试验,采用随机孔隙模型(RVM)与随机球孔模型(RSM)进行超声有限元数值模拟,结合灵敏度分析方法定量反演TBCs的多个弹性常数,并分别与微观力学理论计算以及试验测量的弹性常数进行对比,揭示孔隙不规则形貌对宏观弹性的影响规律。等离子体喷涂Al2O3涂层弹性常数的超声测量、数值模拟以及理论计算结果显示:弹性常数具有明显的弹性各向异性,数值模拟发现基于RSM模型测量的弹性常数值与理论值具有较好的一致性,相对偏差不超过3.32%;基于RVM模型测量的弹性常数值与理论值的相对偏差高达12.53%,孔隙不规则形貌对TBCs宏观弹性具有不可忽略的影响,而且具有不规则形貌的RVM反演结果相较于RSM与试验结果更相近,进一步说明孔隙不规则形貌会显著影响涂层的弹性性能。研究结果为表征TBCs微观结构的复杂形貌提供一定的支撑,对研究TBCs微观结构与弹性性能关系并进一步优化制备工艺具有重要意义。Thermal barrier coatings(TBCs)have excellent properties,including a high melting point,low thermal conductivity,and high thermal expansion coefficient,which can significantly improve the efficiency and extend the service life of high-temperature components in the aerospace industry.Due to the characteristics of the TBC preparation process,pores are inevitably present inside the coatings and significantly affect the mechanical properties of the TBCs,particularly their elastic properties.Therefore,exploring the relationship between the microstructural characteristics of TBCs and the macroscopic elasticity is crucial for optimizing the parameters of the preparation process and predicting the service life.The internal pores of TBCs exhibit complex morphologies,such as irregular shapes and rough boundaries.However,existing research on TBCs based on elliptical approximations have focused on the relationships among the porosity,size,orientation,and macroscopic elasticity without considering the effects of irregular pore morphology on the macroscopic elasticity.In this study,a water-immersion ultrasonic back-reflection experiment was conducted using test samples with an Al2O3 coating plasma-sprayed onto a stainless steel substrate.The experimental setup consisted of an angle meter,a 10 mm thick acrylic glass flat-bottomed reflector,and an SM-J3B-300 water-immersion ultrasonic testing system,which included a GE USIP 40 ultrasonic generator,Tektronix DPO 4034B digital oscilloscope,nominal 5-MHz water-immersion pulse-focusing probe,three-dimensional stepper device,and self-built rotational angle measurement device used for precise control of the sample’s axial rotation angle.The backscattered signal from the flat-bottomed reflector surface at the vertical incidence was used as a reference signal,and the angle meter displayed theθi values.The coating was continuously rotated in the x1-x3 plane from 0°to 90°in increments of 1°.The ultrasonic backscattered signals corresponding to different incident anglesθi were collec

关 键 词：热障涂层 超声反射 孔隙结构 孔隙形貌 弹性各向异性 

分 类 号：TB559[理学—物理]