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Comparative study on microstructure evolution and failure mechanisms of ordinary and refurbished EB-PVD TBC under cyclic oxidation

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Journal of Advanced Ceramics 2023年第9期12卷 1805-1820页

作者： Pan Li xiaochao jin Pin Lu Delin Liu Rende Mou Xueling Fan Xi’an Key Laboratory of Extreme Environmental Serviceability and Protection Technologies School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China AECC Beijing Institute of Aeronautical Materials Beijing 100095China

Refurbishment of thermal barrier coating(TBC)has become a valuable technique to prolong the service life of high-temperature components.This study investigates the effect of the refurbishment process(coating removal and recoating)on the microstructure evolution and physical properties of TBC,including oxidation characteristics,element diffusion behavior,and crack failure mechanisms.The results showed that a certain amount of interdiffusion zone(IDZ)with Cr-rich would be retained in DD6 superalloy substrate after coating removal.The microstructure of the refurbished specimens showed equiaxedβ-NiAl phases,while the ordinary specimens have elongated grain shapes with a high aspect ratio.Moreover,mixed oxides in the refurbished TBC specimens were earlier observed during cyclic oxidation,with a greater thickness compared to ordinary TBC,due to the influence of BC layer phase sizes.The growth mechanism of thermally grown oxide(TGO-Al_(2)O_(3)layer)in the refurbished TBC specimens was also different,resulting from the different mechanisms of mixed oxides growth.Furthermore,under cyclic oxidation with water quenching at 1100℃,the cracks in the refurbished specimen tend to occur in the mixed oxides layer,while the cracks in the ordinary specimen occur in the top coat(TC)layer,attributing to the earlier and thicker mixed oxides layer formed in refurbished specimens.

关键词： thermal barrier coating(TBC)systems coating removal refurbishment cyclic oxidation microstructure evolution failure mechanism

Thermal Analysis of Turbine Blades with Thermal Barrier Coatings Using Virtual Wall Thickness Method

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Computer Modeling in Engineering & Sciences 2023年第2期134卷 1219-1236页

作者： Linchuan Liu Jian Wu Zhongwei Hu xiaochao jin Pin Lu Tao Zhang Xueling Fan Joint Research Center for Extreme Environment and Protection Technology School ofAerospace EngineeringXi’an Jiaotong UniversityXi’an710049China AEEC Sichuan Gas Turbine Establishment Chengdu610500China

Avirtual wall thicknessmethod is developed to simulate the temperature field of turbine bladeswith thermal barrier coatings(TBCs),to simplify the modeling process and improve the calculation efficiency.The results show that the virtualwall thickness method can improve themesh quality by 20%,reduce the number ofmeshes by 76.7%and save the calculation time by 35.5%,compared with the traditional real wall thickness method.The average calculation error of the two methods is between 0.21%and 0.93%.Furthermore,the temperature at the blade leading edge is the highest and the average temperature of the blade pressure surface is higher than that of the suction surface under a certain service condition.The blade surface temperature presents a high temperature at both ends and a low temperature in themiddle height when the temperature of incoming gas is uniformand constant.The thermal insulation effect of TBCs is the worst near the air film hole,and the best at the blade leading edge.According to the calculated temperature field of the substrate-coating system,the highest thermal insulation temperature of the TC layer is 172.01 K,and the thermal insulation proportions of TC,TGO and BC are 93.55%,1.54%and 4.91%,respectively.

关键词： Turbine blade thermal analysis thermal barrier coatings finite element method virtual wall thickness

Quantifying Solid Solution Strengthening in Nickel-Based Superalloys via High-Throughput Experiment and Machine Learning

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Computer Modeling in Engineering & Sciences 2023年第5期135卷 1521-1538页

作者： Zihang Li Zexin Wang Zi Wang Zijun Qin Feng Liu Liming Tan xiaochao jin Xueling Fan Lan Huang State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China AECC Commercial Aircraft Engine Co. Ltd.Shanghai200241China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an710049China

Solid solution strengthening(SSS)is one of the main contributions to the desired tensile properties of nickel-based superalloys for turbine blades and disks.The value of SSS can be calculated by using Fleischer’s and Labusch’s theories,while the model parameters are incorporated without fitting to experimental data of complex alloys.In thiswork,four diffusionmultiples consisting of multicomponent alloys and pure Niare prepared and characterized.The composition and microhardness of singleγphase regions in samples are used to quantify the SSS.Then,Fleischer’s and Labusch’s theories are examined based on high-throughput experiments,respectively.The fitted solid solution coefficients are obtained based on Labusch’s theory and experimental data,indicating higher accuracy.Furthermore,six machine learning algorithms are established,providing a more accurate prediction compared with traditional physical models and fitted physical models.The results show that the coupling of highthroughput experiments and machine learning has great potential in the field of performance prediction and alloy design.

关键词： Multicomponent diffusion multiples solid solution strengthening strengthening models machine learning

Experimental and numerical investigation on the thermal and mechanical behaviours of thermal barrier coatings exposed to CMAS corrosion

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Journal of Advanced Ceramics 2021年第3期10卷 551-564页

作者： Dongxu LI Peng JIANG Renheng GAO Fan SUN xiaochao jin Xueling FAN State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China AEEC Sichuan Gas Turbine Establishment Chengdu 610500China

Calcium-magnesium-alumino-silicate(CMAS)corrosion is a critical factor which causes the failure of thermal barrier coating(TBC).CMAS attack significantly alters the temperature and stress fields in TBC,resulting in their delamination or spallation.In this work,the evolution process of TBC prepared by suspension plasma spraying(SPS)under CMAS attack is investigated.The CMAS corrosion leads to the formation of the reaction layer and subsequent bending of TBC.Based on the observations,a corrosion model is proposed to describe the generation and evolution of the reaction layer and bending of TBC.Then,numerical simulations are performed to investigate the corrosion process of free-standing TBC and the complete TBC system under CMAS attack.The corrosion model constructs a bridge for connecting two numerical models.The results show that the CMAS corrosion has a significant influence on the stress field,such as the peak stress,whereas it has little influence on the steady-state temperature field.The peak of stress increases with holding time,which increases the risk of the rupture of TBC.The Mises stress increases nonlinearly along the thick direction of the reaction layer.Furthermore,in the traditional failure zone,such as the interface of the top coat and bond coat,the stress obviously changes during CMAS corrosion.

关键词： thermal barrier coating(TBC) calcium-magnesium-alumino-silicate(CMAS)corrosion corrosion model temperature field stress field

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精神分裂症患者幻听症状管理的证据总结

中国护理管理 2024年第6期24卷 898-903页

作者：金晓超施忠英李丽周英凤刘晓上海交通大学医学院附属精神卫生中心普通精神科上海市200030 上海交通大学医学院附属精神卫生中心护理部上海市200030 上海交通大学医学院附属精神卫生中心特需病区上海市200030 上海交通大学护理学院复旦大学护理学院

目的:总结国内外精神分裂症患者幻听症状管理的相关证据,为临床开展幻听症状管理实践提供参考。方法:系统检索国内外数据库及指南网站中精神分裂症患者幻听症状管理的相关文献,检索时限为建库至2023年2月,由4名研究者独立进行文献质量... 详细信息

目的:总结国内外精神分裂症患者幻听症状管理的相关证据,为临床开展幻听症状管理实践提供参考。方法:系统检索国内外数据库及指南网站中精神分裂症患者幻听症状管理的相关文献,检索时限为建库至2023年2月,由4名研究者独立进行文献质量评价、证据提取和总结。结果:共纳入16篇文献,包括指南7篇、专家共识1篇、系统评价4篇、随机对照试验3篇、类实验研究1篇,从建立治疗联盟、评估、药物治疗、非药物管理、共病治疗、质量控制6个方面总结了28条证据。结论:本研究总结的精神分裂症患者幻听症状管理的证据为临床实践提供了参考,建议后续进行临床转化,提高护理质量,增强患者对幻听症状的自我管理能力。

关键词：精神分裂症幻听症状管理非药物管理证据总结

SiC/SiC复合编织管的抗热冲击性能与失效机理研究

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应用力学学报 2024年第2期41卷 288-296页

作者：胡庆宽许琦鹏万志慧杨保建周为晋小超河南航天精工制造有限公司河南省紧固连接技术重点实验室信阳464000 西安交通大学航天航空学院极端环境与防护技术联合研究中心西安710049

以二维二轴编织的SiC/SiC复合编织管为研究对象,研究其抗热冲击性能及失效机理。自主搭建了基于石英灯辐照加热的循环热冲击试验平台,基于该平台开展了SiC/SiC复合编织管的循环热冲击试验考核,并对循环热冲击后的复合编织管进行了径向... 详细信息

以二维二轴编织的SiC/SiC复合编织管为研究对象,研究其抗热冲击性能及失效机理。自主搭建了基于石英灯辐照加热的循环热冲击试验平台,基于该平台开展了SiC/SiC复合编织管的循环热冲击试验考核,并对循环热冲击后的复合编织管进行了径向压缩测试,探究了复合编织管力学性能与破坏机理,拟合得到了热冲击强度退化经验公式。研究结果表明,搭建的循环热冲击试验平台能够模拟快速升降温的实际服役环境,最高升温、降温速率在试验过程中分别可达约40、60℃/s。随着热冲击循环次数的增加,SiC/SiC复合编织管环向拉伸强度下降,且降幅随之增大。热冲击产生的热应力导致纤维周围的基体产生微裂纹,弱化了纤维束与基体之间的连接,这是复合编织管强度降低的原因之一。拟合的强度退化经验公式能够准确描述强度退化规律,可以满足工程应用需求。

关键词：陶瓷基复合材料 SiC/SiC复合编织管石英灯辐照加热热冲击失效机理

精神分裂症社会心理干预临床实践指南的系统评价

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护士进修杂志 2024年第1期39卷 52-58页

作者：金晓超周英凤施忠英李丽上海交通大学医学院附属精神卫生中心上海200030 复旦大学护理学院上海200032

目的对精神分裂症社会心理干预相关指南进行系统评价,比较社会心理干预推荐意见的差异。方法计算机检索国内外指南网、相关学会网站及数据库中关于精神分裂症社会心理干预的相关指南,检索时限为建库至2022年6月30日。采用指南方法学... 详细信息

目的对精神分裂症社会心理干预相关指南进行系统评价,比较社会心理干预推荐意见的差异。方法计算机检索国内外指南网、相关学会网站及数据库中关于精神分裂症社会心理干预的相关指南,检索时限为建库至2022年6月30日。采用指南方法学质量评价工具AGREEⅡ对指南进行质量评价,比较精神分裂症社会心理干预推荐意见的证据质量和推荐强度,分析推荐意见间的差异。结果共纳入指南7篇,3篇为A级推荐,4篇为B级推荐。共提取12项社会心理干预措施,7篇指南中均建议精神分裂症患者应接受认知行为治疗和家庭治疗,其他社会心理干预措施推荐意见间存在明显差异。结论指南的总体质量尚可,需详细阐述各推荐意见的实施策略,提供资源,探索长期应用效果,促进精神分裂症患者全面康复,为临床护理实践提供证据支持。

关键词：精神分裂症社会心理干预临床实践指南系统评价护理

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航空发动机涡轮叶片接触式测温技术应用进展

航空工程进展 2023年第1期14卷 1-12页

作者：胡娜赵伟晋小超范学领西安交通大学航天航空学院西安710049 中国航发四川燃气涡轮研究院强度传动试验技术研究室绵阳621000

航空发动机涡轮叶片测温技术能够揭示涡轮叶片的温度分布情况,对其开展性能评估、失效分析和优化设计具有重要意义。涡轮进口温度的不断提升对应用于航空发动机涡轮叶片的测温技术提出了更高的要求。现有的航空发动机涡轮叶片接触式测... 详细信息

航空发动机涡轮叶片测温技术能够揭示涡轮叶片的温度分布情况,对其开展性能评估、失效分析和优化设计具有重要意义。涡轮进口温度的不断提升对应用于航空发动机涡轮叶片的测温技术提出了更高的要求。现有的航空发动机涡轮叶片接触式测温技术可采集叶片表面温度和近表面气流温度,本文主要介绍了三种应用于涡轮叶片的接触式测温技术,包括薄膜热电偶、测温晶体和示温漆,简要说明了三种测温技术的工作原理,归纳了国内外应用现状,总结了各自的优势与不足,并对其发展方向进行了展望。

关键词：航空发动机涡轮叶片接触式测温薄膜热电偶测温晶体示温漆

糖尿病高危足患者足部护理教育证据应用审查及障碍因素分析

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中华现代护理杂志 2022年第15期28卷 2030-2035页

作者：金晓超吴荣张翠娣上海交通大学医学院附属精神卫生中心普通精神科上海200030 上海中医药大学附属龙华医院内分泌科上海200032 上海中医药大学护理学院上海201203

目的了解糖尿病高危足患者足部护理教育证据临床应用现状,分析障碍因素并制订干预策略,为循证证据向临床实践转化提供参考。方法采用便利抽样法,于2019年4—6月选取上海中医药大学附属龙华医院内分泌科12名护士、49例糖尿病高危足患者... 详细信息

目的了解糖尿病高危足患者足部护理教育证据临床应用现状,分析障碍因素并制订干预策略,为循证证据向临床实践转化提供参考。方法采用便利抽样法,于2019年4—6月选取上海中医药大学附属龙华医院内分泌科12名护士、49例糖尿病高危足患者为研究对象。引入糖尿病高危足患者足部护理教育证据15条,根据证据制订10条审查指标开展临床现状审查,依据审查结果展开障碍因素分析。结果10条审查指标的临床依从率为0~43%,其中糖尿病高危足患者足部护理知识、信念、行为的标准化得分分别为68.32%、61.00%、59.44%,护士足部护理知识、信念、行为的标准化得分分别为75.97%、54.17%、52.78%。障碍因素主要包括缺乏糖尿病高危足足部护理教育循证护理实践方案、未引入糖尿病高危足筛查工具、未开展多学科足部护理教育、健康教育形式单一、护士的足部护理教育知信行水平较低、缺乏培训、护士不重视效果评价等。结论糖尿病高危足患者足部护理教育证据尚未有效转化于临床实践,应根据干预策略构建循证实践方案,缩短临床实践与证据间的差距。

关键词：糖尿病足足部护理教育证据临床应用审查障碍因素