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CMAS attack behavior of air plasma sprayed thermal barrier coatings with big pores

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Journal of the European Ceramic Society 2022年第13期42卷 6159-6169页

作者： Shan, Xiao Wu, Di Cai, Huangyue Luo, Lirong Yang, Lixia Jia, Libing Guo, Fangwei Zhao, Xiaofeng Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China Aero Engine Corporation of China Shanghai Commercial Aircraft Engine Manufacturing Co. Ltd Shanghai201306 China Engineering Research Center of Nano-Geo Materials of Ministry Education Faculty of Materials Science and Chemistry China University of Geosciences Wuhan430074 China College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing210016 China Power Generation Siemens Energy Co. Ltd Shanghai200082 China

Previous studies indicated that big globular pores in air plasma sprayed (APS) thermal barrier coatings (TBCs) are more likely to remain after calcium-magnesium-alumino-silicates (CMAS) attack than are small ones. In this research, therefore, the CMAS attack behavior of an APS TBC with more big globular pores was investigated. It was demonstrated that the more-big-globular-pores APS TBC exhibited better resistance to exfoliation and intergranular corrosion, and chemical degradation than normal APS TBCs, while its pores can be easily filled by CMAS. Analysis on pore structures and CMAS infiltration characteristics indicated that the morphologies of the transition regions between the globular and the crack network pores may play an import role in determining the CMAS filling behavior for globular pores in APS TBCs. © 2022 Elsevier Ltd

关键词： Plasma spraying

Investigation of Microstructures and High-Temperature Tensile Behavior of Heat Treated Gtd222 Nickel-Based Superalloy Prepared by Selective Laser Melting

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SSRN 2023年

作者： Lv, Yuting Dong, Hao Lang, Xianwei Zhang, Qiang Deng, Wentang Jiang, Di Wang, Rui Wei, Guijiang College of Mechanical and Electronic Engineering Shandong University of Science and Technology Shandong Qingdao266590 China Gaona Aero Material Co. Ltd. China Beijing Key Laboratory of Advanced High Temperature Materials Central Iron & Steel Research Institute China Shanghai Key Laboratory of Advanced High Temperature Materials and Precision Forming Shanghai Jiao Tong University 800 Dongchuan Road Shanghai200240 China Affiliated Hospital of Youjiang Medical University for Nationalities Guangxi Baise533000 China

In this study, various heat treatment including direct aging and solution aging treatment were performed on the selective laser melted (SLMed) GTD222 nickel-based superalloy, and the microstructures and high-temperature tensile behavior of the superalloys were systematically investigated. The results indicate that, in comparison to the as-deposited superalloy, both direct aging and solution aging lead to a significant enhancement in high-temperature strength and ductility. The directly aged superalloy exhibits a higher yield strength, while the solution-aged superalloy displays superior elongation. Specifically, at a tensile temperature of 760 °C, the superalloy subjected to a solution treatment at 1240 °C demonstrates the most favorable tensile properties, boasting a tensile strength of 835 MPa, an elongation rate of 6.5 %, and a reduction in area of 13 %. This study also provides a detailed discussion of the high temperature tensile behavior of the SLMed GTD222 superalloy after heat treatment. © 2023, The Authors. All rights reserved.

关键词： Superalloys

Effect Mechanism of Paramagnetic Element Cu In-Situ Alloying on the Microstructure and Magnetic Properties of Slm-Formed Nifemo Alloys

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SSRN 2024年

作者： Xiong, Falin Yang, Jiaoxi Guo, Donghai Liu, Wenfu Du, Zhicheng Yang, Feng Li, Ran Ge, Xueyuan Wang, Miaohui Xu, Hongchao Zhou, Zheng Institute of Laser Engineering Faculty of Material and Manufacturing Beijing University of Technology Beijing100124 China Central Iron and Steel Research Institute Beijing100081 China State Key Laboratory for Advanced Forming Technology and Equipment China Academy of Machinery and Technology Beijing100083 China Beijing National Innovation Institute of Light weight Ltd. Beijing100083 China Beijing Tieke Shougang Railway-Tech Co. Ltd Beijing100083 China

NiFeMo alloy possesses exceptional soft magnetic properties, and suffers significantly from the SLM process. The major objective of this study is to explore the relationship between microstructure and magnetic properties of SLM formed (NiFeMo)100-xCux alloy (x=0 wt.%, 0.5 wt.%, 0.8 wt.%, 1.1 wt.%, 1.4 wt.%, 1.7 wt.%, and 2.0 wt.%) by adding Cu in-situ alloying, and develop a new method to adjust the magnetic properties of SLM molding materials. The structure and magnetic properties of the alloy samples were characterized using scanning electron microscopy (SEM), X-ray diffraction, electron backscattering diffraction (EBSD), DC B-H hysteresis map, and transmission electron microscopy (Titan-G2) techniques. The results show that (NiFeMo)100-xCux alloy exhibits FCC γ-(Ni, Fe) solid solution structure within the range of added Cu content in this study. In the central region of the melt pool, columnar crystals grow in the direction of the temperature gradient, and the average grain size (D) gradually decreases with the increase of the Cu content of in situ alloying, while the content of low-angle grain boundaries (LAGS) decreases. Cu atoms exist in γ-(Ni, Fe) solid solution by replacement solid solution, changing the crystal structure and leading to lattice distortion. The (NiFeMo)98Cu2 alloy has an average crystal plane spacing d of about 0.2261 nm along the (1[[EQUATION]]) γ-(Ni, Fe) direction, and a lattice distortion ∆Ε of about 1.09%. The saturation magnetic induction (BS) increases and then decreases with increasing Cu additions, with BS > 0.7 T for NiFeMo alloys with Cu additions of 0.8 wt.%, 1.1 wt.%, and 1.4 wt.%. The coercivity (HC) generally decreased with the increase of Cu content, and HC © 2024, The Authors. All rights reserved.

关键词： Alloying

Constructing Multilevel Structure with Microdomains of Oxides on Three-Dimensional High-Entropy Alloy Support Toward Efficient Oxygen Evolution

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SSRN 2022年

作者： Zhang, Shaofei Guo, Jing Li, Tiantian Sun, Jinfeng Meng, Yongqiang Kang, Jianli Tan, Linli Zhang, Zhijia Hebei Key Laboratory of Flexible Functional Materials Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and Engineering Hebei University of Science and Technology Shijiazhuang050018 China Key laboratory of Advanced Ceramics and Machining Technology Ministry of Education School of Materials Science and Engineering Tianjin University Tianjin300072 China Key Laboratory of Green Manufacturing of Super-light Elastomer Materials of State Ethnic Affairs Commission College of Intelligent systems Science and Technology Hubei Minzu University Enshi445000 China State Key Laboratory of Separation Membrane and Membrane Process Tianjin Municipal Key Laboratory of Advanced Fibers and Energy Storage School of Materials Science and Engineering Tiangong University Tianjin300387 China

High-entropy alloys (HEAs) with maximized configurational entropy has shown a great promise for anodic water splitting, but still limited to their unsatisfactory configuration and large-scaled application. In the present study, a series of dual-phase electrodes with spinel MnCr2O4 microdomains pinning on large-scaled and flexible surface oxidized high-entropy alloys (O-HEA) as highly efficient electrocatalysts is prepared by combining modified non-solvent induced phase separation (NIPs) and metallurgy approaches. The precipitation of MnCr2O4 microdomains from O-HEA support not only result in a shrinking of lattice constant of HEA but also lead to a surface reconstruction. Besides, the MnCr2O4 microdomains can synergy with reconstructed O-HEA support to increase the hydrophilic property and provide high-efficient electron/ion transport, thus promoting the O-O coupling. By virtues of the multilevel structure, the O-HEA2 electrode exhibits impressive oxygen evolution properties with a low overpotential of 268 mV and Tafel slope of 51.6 mV dec−1 in 1M KOH at 10 mA cm−2. It also exhibits a long durability exceed 70 h at 25 mA cm−2. This work provides a new prospect for the rational design of large-scaled and self-supported 3D HEA based electrodes for energy conversion applications. © 2022, The Authors. All rights reserved.

关键词： Catalyst activity

Experimental study on the frosting/defrosting performance of super hydrophobic evaporator based on micro-nano technology

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Experimental study on the frosting/defrosting performance of...

2020 International Conference on Artificial Intelligence and Electromechanical Automation, AIEA 2020

作者： Du, Weixiao Liu, Meng Zhan, Li Liu, Feng Woonbong, Hwang Beijing National Innovation Institute of Lightweight Ltd State Key Laboratory of Advanced Forming Technology and Equipment Beijing China Pohang Gyeongbuk790-784 Korea Republic of

ISBN: (数字)9781728182889

ISBN: (纸本)9781728182889

In order to improve the heat exchanger efficiency, reduce energy consumption, the anti-frosting performance of superhydrophobic evaporator was investigated experimentally. By comparing the frosting time, form, process, surface condition and defrosting time, form, process and surface condition of hydrophilic evaporator and superhydrophobic evaporator, the frosting/defrosting principle of superhydrophobic evaporator was analyzed. Conclusion showed that the super hydrophobicity can delay frosting formation initially, reduce frosting accumulation effectively. In the process of frosting, the energy consumption ratio of hydrophilic evaporator and superhydrophobic evaporator was obtained. It declared that the superhydrophobic evaporator had better anti-frosting performance and higher energy efficiency ratio than the hydrophilic evaporator. © 2020 IEEE.

关键词： Energy utilization

Exceptional Combination of Mechanical Properties and Cavitation Erosion-Corrosion Resistance in a Fe23.7co23.8ni23.8cr23.7mo5 Multi-Principal Element Alloy

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SSRN 2024年

作者： Niu, Jiacheng Fu, Zhiqiang Hou, Guoliang Chen, Qiang Yao, Ning Chen, Weiping Lu, Tiwen Chu, Chenliang Wen, Haiming Guangdong Key Laboratory for Advanced Metallic Materials Processing South China University of Technology Guangdong Guangzhou510640 China National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of Technology Guangzhou510640 China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou730000 China Southwest Technology and Engineering Research Institute Chongqing400039 China School of Mechanical and Power Engineering East China University of Science and Technology Shanghai200237 China Department of Materials Science and Engineering Missouri University of Science and Technology RollaMO65409 United States

This study analyzed cavitation erosion (CE) and cavitation erosion-corrosion (CE-C) of single-phase face-centered cubic structured Fe23.7Co23.8Ni23.8Cr23.7Mo5 multi-principal element alloy (MPEA) with varying grain sizes obtained through post-deformation annealing. The ~4.1 μm (average grain size) sample showed an excellent combination of strength and ductility and the best electrochemical corrosion resistance in 3.5 wt.% NaCl solution and demonstrated superior resistance to pure CE and CE-C compared to other grain sizes (~10.3 and ~15.2 μm). The ~4.1 μm sample had better CE-C resistance due to its excellent mechanical properties, high work hardening ability, and excellent anti-corrosion performance. © 2024, The Authors. All rights reserved.

关键词： Erosion

Microstructure and electrochemical corrosion behavior of selective laser melted Ti−6Al−4V alloy in simulated artificial saliva

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Transactions of Nonferrous Metals Society of China 2021年第1期31卷 167-177页

作者： Jiang JU Jing-jing LI Min JIANG Meng-ya LI Li-xiang YANG Kai-ming WANG Chao YANG Mao-dong KANG Jun WANG Institute of Solidification Science and Technology School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming Shanghai Jiao Tong UniversityShanghai 200240China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Ti−6Al−4V alloy was fabricated via selective laser melting(SLM)to improve its corrosion resistance for *** microstructure and electrochemical corrosion behavior were investigated using scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),electrochemical test and contact angle *** can be found that the as-selective laser melted(as-SLMed)Ti−6Al−4V alloys showβcolumnar microstructure in building direction and nearly circular checkerboard microstructure in scanning direction,while the wrought and wrought+HT samples exhibit equiaxed *** as-SLMed Ti−6Al−4V alloy exhibits better corrosion resistance than the wrought and wrought+HT samples due to hydrophobicity,high grain boundary density and uniform distribution of alloying elements in simulated artificial saliva at 37℃.

关键词： Ti−6Al−4V alloy selective laser melting microstructure electrochemical corrosion behavior

Dt300 Ultra-High Strength Steel Fabricated Using Selective Laser Melting: Densification, Microstructure, and Mechanical Properties

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SSRN 2022年

作者： Jiang, Chenyang Li, Xiaoqiang Luo, Hao Li, Jingmao Qu, Shengguan Yang, Chao National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of Technology Guangzhou510640 China Guangdong Key Laboratory for Advanced Metallic Materials Fabrication and Forming China Institute of New Materials Guangdong Academy of Science Guangzhou510650 China College of Materials Science and Engineering China

DT300 ultra-high strength steel has been widely used due to its combination of high mechanical properties and a relative low cost. However, the traditional casting and forging process can hardly meet the rising needs of producing parts with complicated shapes and high precision. In this study, selective laser melting was utilized to fabricate DT300 steel for the first time. Fully dense (> 99% relative density) parts were successfully fabricated and the types and formation mechanism of defects under different conditions are discussed in detail. The average equivalent diameter of martensite laths is only 0.64 μm, and the retained austenite content of horizontal and vertical section is 5.6% and 7.1% in volume fraction, respectively. The fine prior austenite grain boundaries are continuously and uniformly distributed both in horizontal and vertical sections. Both martensite and austenite show strong texture orientation, which is closely related to the laser scanning direction of each layer. The specimens fabricated by the optimized parameter M8 (250 W laser power, 800 mm/s laser scanning speed, 90 μm hatch spacing) possess outstanding mechanical properties (yield strength up to 1451 MPa, ultimate tensile strength up to 1813 MPa, 19.21% elongation to fracture) as well as outstanding surface quality (Ra of 14.37 ± 2.15 μm). The mechanical properties of SLM fabricated DT300 steel are much higher than that of as-cast condition and are counterpart to the wrought one with post heat treatment. © 2022, The Authors. All rights reserved.

关键词： Surface roughness

Chemical composition analysis on industrial scale ingots and castings of TiAl alloys

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China Foundry 2020年第6期17卷 441-446页

作者： Xian-fei Ding Yi-qun Zhao Jia-bin Zuo Xin Feng Hai Nan Yong-feng Liang Yan-qing Su Cast Titanium Alloy R&D Center Beijing Institute of Aeronautical MaterialsBeijing 100095China Beijing Engineering Research Center of Advanced Titanium Alloy Precision Forming Technology Beijing 100095China BAIMTEC Material Co. Ltd.Beijing 100094China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology HarbinHarbin150001China

The chemical composition variation of the TiAl-4722 alloys was examined in a batch of the industrial scale master ingots,and in the corresponding castings prepared by conventional vacuum arc remelting(VAR)combined with induction skull melting(ISM)and investment casting *** content changes of major elements and interstitial elements were evaluated based on the chemical analysis at the top and bottom of the ingots and *** show that the contents of C,N,H,Fe and Si have almost no change in the ingots and castings,suggesting that the chemical analysis on these elements can be based on the batch *** O content keeps almost the same in different ingots,but exhibits relatively large differences in castings,which was probably influenced by the reaction between the shell mold and the molten alloy,and the spalling of face coat of the shell mold during *** the major elements of Al,Nb and Cr,the composition difference between the top and the bottom of the ingots is less than that of the *** for the O element,the trend is different,especially for the castings,suggesting that the investment casting is a homogenization process for Cr and Nb,but a differentiation process for *** contents of major elements in castings fluctuate mainly in the same range as that in the ingots,indicating that the contents of the major elements are controllable during investment casting.

关键词： TiAl alloys melting casting chemical composition casting ingot