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2023 4th International Conference on Mechanical Engineering and materials, ICMEM 2023

作者： You, Long Liu, Changkui Chen, Hehe Fan, Hao AECC Beijing Institute of Aeronautical Materials Key Laboratory of Aeronautical Materials Testing and Evaluation Aero Engine Corporation of China Beijing100095 China College of Materials Science and Engineering Nanchang Hangkong University Nanchang330063 China

Loosening of bolted joint structure is a critical failure mode mainly caused by the slippage and friction behaviours on the thread and bearing surfaces. Domestic and foreign scholars have conducted a series of studies on the loosening mechanism and anti-loosening methods of bolted joint structures;however, there are fewer summaries on the influencing factors of loosening of bolted joint structures. This paper takes the phenomenon of loosening of bolted joint structure as the research object, summarizes the research method of loosening of bolt joint structure and the influencing factors, and summarizes the influencing law of loosening of bolted joint structure in four aspects, namely, preload force, external load factors, structural factors, and operating temperature, to provide references for the design of anti-loosening of bolted joint structure. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Bolted joints

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Indium oxide buffer layer for perovskite/Si 4-terminal tandem solar cells with efficiency exceeding 30%

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Journal of Energy Chemistry 2025年第3期102卷 189-196页

作者： Liming Du Can Li Yuhui Jiang Fangfang Cao Chunmei Jia Zhi Wan Rui Meng Jishan Shi Chuanxiao Xiao Zhe Liu Zhen Li State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi'an710072ShaanxiChina Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201ZhejiangChina Ningbo New Materials Testing and Evaluation Center Co. Ltd.Ningbo 315201ZhejiangChina

Perovskite/Si tandem solar cells(TSCs)present great potential to surpass the Shockley-Queisser limit of single-junction solar cells for further advancing the power conversion efficiency(PCE)of solar ***,the fabrication of TSCs usually encounters challenge of selecting suitable sputtering buffer layer(SBL)to prevent the bombardment during the transparent electrode ***,we introduce an indium oxide(In_(2)O_(3))buffer layer via e-beam deposition to fabricate semi-transparent perovskite solar cells(ST-PSCs).The optical transmittance and electrical conductivity of In_(2)O_(3)highly depend on the deposition *** deposition rate results in high ratio of metallic indium in the film,which causes severe parasitic absorption.A 20 nm-thick In_(2)O_(3)film deposited at lower rate demonstrated high conductivity,transmittance and robust protection during sputtering.A 1.68 eV ST-PSC incorporating this In_(2)O_(3)buffer layer exhibits a champion PCE of 20.20%,demonstrating the excellent optoelectronic and protective properties of In_(2)O_(3).When combined with a Si subcell,the 4-terminal TSC obtains a remarkable PCE of 30.04%,Importantly,the unencapsulated ST-PSC maintained 80%of initial PCE after 423 h of continuous light soaking in N_(2).This work has provided a facile and instrumental transparent SBL strategy for perovskite/Si TSCs.

关键词： E-beam deposition Sputtering Transparent electrode Perovskite solar cells In_(2)O_(3)

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Detection methods and bearing failure characteristics analysis related to grinding burns 2

Detection methods and bearing failure characteristics analys...

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2nd International Conference on Frontier materials, ICFM 2023

作者： Hou, Xue Qin Liu, Yong Bao Liu, Yu Liu, Chang Kui Zhang, Zheng Hutao, Chun Wei, Xun Kai AECC Beijing Institute of Aeronautical Materials Beijing100095 China AVIC Failure Analysis Center Beijing100095 China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing100095 China Key Laboratory of Science and Technology on Aeronautical Materials Testing and Evaluation Aeroengine Corporation of China Beijing100095 China School of Material Science and Engineering Beihang University Beijing100191 China AECC Harbin Bearing Co. Ltd. Harbin150025 China Beijing Aeronautical Technology Research Center Beijing100024 China

Grinding burn is one of the bearing failure causes for components. In order to quickly confirm that grinding burn is the cause of bearing failure, detection methods for the grinding burns and characteristics of bearing failure caused by grinding burns have been studied in this paper. The results show that cold acid pickling examination, microhardness test and Barkhausen noise analysis can be used in the detection of heavy grinding burns but have several disadvantages to hinder their application on the detection of slight grinding burns. A grinding burn detection procedure is recommended for the analysis of bearing failure induced by grinding burn. It has been found that the modes of bearing failure induced by grinding burns were contact fatigue spalling developed from the contact fatigue crack, the propagation mechanism of the contact fatigue crack was obtained. And the unique phenomenon of fracture or fragmentation with cracks distributed in the origin or surrounding the spalling pit of the grinding burn layer was also obtained. Based on the above results the future work on detection methods and influence on bearing failure mechanism and life of grinding burn are proposed. © 2023 Published under licence by IOP Publishing Ltd.

关键词： Spalling

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MULTIBRANCH BLOCK-BASED GRAIN SIZE CLASSIFICATION OF HYBRID DISK USING ULTRASONIC SCATTERING: A DEEP LEARNING METHOD

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materials evaluation 2024年第4期82卷 38-52页

作者： Liu, Xiao Sha, Zheng-Xiao Liang, Jing AECC Beijing Institute of Aeronautical Materials Beijing100095 China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing100095 China Key Laboratory of Science and Technology on Aeronautical Materials Testing and Evaluation Aeroengine Corp. of China Beijing100095 China

To assess the grain size of hybrid disks, we propose a simple network architecture—the wide-paralleled convolutional neural network (WP-CNN)—based solely on multibranch blocks and create a grain size classification model based on it. Multibranch blocks are used to enhance the capability of feature extraction, and the global average pooling layer was implemented to reduce the number of model parameters. To train and test the model, a dataset of ultrasonic scattering signals from a hybrid disk was constructed. The WP-CNN structure and hyperparameter selection were examined using the training set. The experiment demonstrated that, compared to traditional 1D convolutional neural network, 1D ResNet, and InceptionTime, the classification accuracy of this method can reach 92.3%. A comparison is made with the empirical mode decomposition scattering model and frequency spectra tree model. The proposed network provides accurate classification of grain size without physical parameters and specific physical models. The results show the deep learning method has the feasibility to evaluate hybrid disk grain size distribution. ©2024 American Society for Nondestructive testing.

关键词： Convolutional neural networks

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Quality assessment of friction-stir-welded aluminum alloy welds via three-dimensional force signals

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Advances in Manufacturing 2024年第1期12卷 61-75页

作者： Ji-Hong Dong Yi-Ming Huang Jia-Lei Zhu Wei Guan Xu-Kai Ren Huan-Wei Yu Lei Cui Beijing Institute of Petrochemical Technology Beijing102617People’s Republic of China Beijing Academy of Safety Engineering and Technology Beijing102617People’s Republic of China AVIC Manufacturing Technology Institute Beijing100024People’s Republic of China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300350People’s Republic of China Shaoxing Special Equipment Testing Institute Shaoxing Key Laboratory of Special Equipment Intelligent Testing and EvaluationShaoxing312071ZhejiangPeople’s Republic of China

An online detection technology must be developed for realizing the real-time control of friction stir *** this study,the three-dimensional force exerted on a material during friction stir welding was collected synchronously and the relationship between the forces and welding quality was *** results indicated that the fluctuation period of the traverse force was equal to that of the lateral force during the stable welding *** phase difference between two horizontal forces wasπ/*** values of the horizontal forces increased with welding speed,whereas their amplitudes remained the *** proposed force model showed that the traverse and lateral forces conformed to an elliptical curve,and this result was consistent with the behavior of the measured *** variational mode decomposition was used to process the plunge *** intrinsic mode function that represented the real fluctuation in the plunge force varied at the same frequency as the spindle rotational *** tunnel defects occurred,the fluctuation period features were consistent with those obtained during normal welding,whereas the ratio parameter defined in this study increased significantly.

关键词： Friction stir welding(FSW) Three-dimensional force model Variational mode decomposition Tunnel defect

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Effect of Different Scanning Modes and Heat Treatment on Microstructure and Mechanical Properties of GH4169 Manufactured by Selective Laser Melting 5th

Effect of Different Scanning Modes and Heat Treatment on Mic...

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5th China Aviation science and technology Conference, 2021

作者： Zhou, Jingyi Wei, Zhenwei Tang, Siyi Zhao, Wenxia Guo, Shaoqing Wang, Jian Zhao, Zijun AECC Beijing Institute of Aeronautical Materials Beijing100095 China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing100095 China Key Laboratory of Aeronautical Materials Testing and Evaluation Aero Engine Corporation of China Beijing100095 China Aviation Key Laboratory of Science and Technology on Materials Testing and Evaluation Beijing100095 China Aero Engine Corporation of China Beijing100097 China

ISBN: (纸本)9789811674228

GH4169 superalloy was prepared by selective laser melting technique. The samples were obtained by scanning in a single direction per layer and scanning in a 90° direction per layer, respectively. The microstructure and precipitated phase were compared and analyzed by OM, SEM and EDS to investigate the non-equilibrium microstructure characteristics and the influence mechanism on mechanical properties of laser additive manufacturing materials of GH4169 under three heat treatment systems. The results show that in the X direction of laser scanning deposition, the tensile strength at room temperature of the material with the same scanning direction of each layer is 4.5% higher than that of the material with the scanning direction of 90°, and the reduction of area is 75.6% higher. After solution and aging treatment, δ phase was precipitated and Laves phase was partially dissolved, but the element segregation in the remelting zone between the cladding layers was not completely eliminated. Homogenization treatment at 1050 ℃ for 1h promotes uniform distribution of segregation elements in cladding layer, remelting layer and dendrite. After homogenization treatment at 1100 ℃ for 1h, Laves phase was fully redissolved, and δ phase and strengthening phase γ ‘ were precipitated again after solution and aging. After heat treatment, the tensile strength at room temperature of the samples prepared by the two laser scanning methods is basically the same in the X direction. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Scanning

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Fracture failure analysis of sensor combination pipes

Fracture failure analysis of sensor combination pipes

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2022 International Conference on Optoelectronic Information and Functional materials, OIFM 2022

作者： Huanping, Kong Changkui, Liu Delin, Liu Aecc Beijing Institute of Aeronautical Materials Beijing China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing China Key Lab. of Sci. and Technol. on Aero. Mat. Test. and Evaluation of Aero Engine Corporation of China Beijing China Aviation Key Laboratory of Science and Technology on Materials Testing and Evaluation Beijing China Aecc Failure Analysis Center Beijing China

ISBN: (数字)9781510655126

ISBN: (纸本)9781510655119

The sensor combination pipes fractured during operation. Through macro and micro morphology observation, energy spectrum analysis, metallographic examination and hardness test, the pipes failure properties and reasons were determined. The results showed that the failure property of dynamic pressure pipe was stress corrosion fracture, and the failure property of the static pressure pipe was corrosion fatigue cracking. The pipes failure was related to the absence of stress relief annealing, and mechanical damage on the pipe surface promoted static pressure pipe failure. © 2022 SPIE.

关键词： Corrosion fatigue

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The Evolution Behaviors of Carbides in the Cobalt-Base Superalloy During the Long-Term Heat-Treatments

SSRN

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SSRN 2024年

作者： Teng, Chaoyi Liu, Changkui Liang, Daizong Zhang, Lihui Huang, Qiang AECC Beijing Institute of Aeronautical Materials Beijing100095 China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing China Key Laboratory of Aeronautical Materials Testing and Evaluation Aero Engine Corporation of China Beijing China Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing China

The carbides evolution behaviors in the equiaxed-crystal cast cobalt-base superalloy during the long-term heat-treatments were studied. The heat-treatment conditions were chosen referred to the real service conditions of the turbine vanes in aero-engines. The Type I M23C6-matrix and Type II M7C3-matrix eutectics were found in the as-cast alloy, but only M23C6-matrix eutectic was found in the heat-treated alloys. The new potential mechanism of the M7C3→M23C6 transformation is proposed. The M23C6-matrix eutectics went through the further decomposition, but large amounts of the lath-like secondary M23C6 formed during the heat-treatments. Regarding the MC carbides, the temperature and duration time of the heat-treatments had significant impacts on their morphologies. The new explanation for the serrations on the primary MC carbide edges after the heat-treatment is proposed. © 2024, The Authors. All rights reserved.

关键词： Eutectics

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Fracture Failure Analysis of Gear Teeth 6

Fracture Failure Analysis of Gear Teeth

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2021 6th International Conference on Applied Mechanics and Structural materials, AMSM 2021

作者： Liu, Chunjiang Ouyang, Kang Jiang, Tao Liu, Changkui AECC Beijing Institute of Aeronautical Materials Beijing100095 China Failure Analysis Center of Aviation Industry Corporation of China Beijing100095 China Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation Beijing100095 China Aviation Key Laboratory of Science and Technology on Materials Testing and Evaluation Beijing100095 China Wuhu Machinery Plant Wuhu241007 China

Gears are important transmission components in the field of aviation industry. Failure cases such as fatigue fracture and fatigue spalling often occur due to poor conditions, and the status of teeth surface is usually one of the important elements for the failure cause analysis, but few have analyzed how the machining status of gear end surface affects the fracture failure. In this paper, one engagement failure of two gears was studied, and the failure phenomenon is as follows: all teeth of the driving gear fractured, two adjacent teeth of the driven gear fractured and several locations of teeth bottom cracked. According to the fracture morphology of the gear, it is judged that the driven gear fatigue-cracked firstly, and the fatigue zone is located at the lower end surface rather than the tooth bottom. Material structure, machining status of gear end surface, and the thickness of nitriding layer were inspected. In addition, the difference of the machining status between the lower and the upper end surface was analyzed. The results show that compared to the upper end surface, the lower end surface is smoother and the grinding amount is relatively larger. The residual stress tested by XRD shows that there is a residual compressive stress of about 84 MPa on the upper end surface and a residual tensile stress of about 238 MPa on the lower end surface. The tensile stress and the working stress cause the local stress level of the lower end surface of the gear to be higher than the fatigue strength, causing fatigue cracking from the lower end surface. © 2022 Institute of Physics Publishing. All rights reserved.

关键词： Tensile stress

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Phase-stable wide-bandgap perovskites enabled by suppressed ion migration

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Journal of Energy Chemistry 2024年第9期96卷 120-128页

作者： Zhiyu Gao Yu Zhu Jingwei Zhu Cong Chen Zongjin Yi Yi Luo Yuliang Xu Kai Wu Tianshu Ma Fangfang Cao Zijun Chen Fang Yao Juncheng Wang Wenwu Wang Chuanxiao Xiao Hao Huang Hongxiang Li Qianqian Lin Pei Cheng Changlei Wang Xia Hao Guanggen Zeng Dewei Zhao College of Materials Science and Engineering&Institute of New Energy and Low-Carbon Technology&Engineering Research Center of Alternative Energy Materials and Devices Ministry of EducationSichuan UniversityChengdu 610065SichuanChina School of Optoelectronic Science and Engineering&Collaborative Innovation Center of Suzhou Nano Science and Technology Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Lab of Modern Optical Technologies of Education Ministry of ChinaSoochow UniversitySuzhou 215006JiangsuChina Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201ZhejiangChina Ningbo New Materials Testing and Evaluation Center Co.Ltd Ningbo 315201ZhejiangChina State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structure&School of Resources Environment and MaterialsGuangxi UniversityNanning 530004GuangxiChina Key Lab of Artificial Micro-and Nano-Structures of Ministry of Education of China School of Physics and TechnologyWuhan UniversityWuhan 430072HubeiChina College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065SichuanChina

Wide-bandgap(>1.7 eV)perovskites suffer from severe light-induced phase segregation due to high bromine content,causing irreversible damage to devices ***,the strategies of suppressing photoinduced phase segregation and related mechanisms have not been fully ***,we report a new passivation agent 4-aminotetrahydrothiopyran hydrochloride(4-ATpHCl)with multifunctional groups for the interface treatment of a 1.77-eV wide-bandgap perovskite film.4-ATpH^(+)impeded halogen ion migration by anchoring on the perovskite surface,leading to the inhibition of phase segregation and thus the passivation of defects,which is ascribed to the interaction of 4-ATpH^(+)with perovskite and the formation of low-dimensional ***,the champion device achieved an efficiency of 19.32%with an open-circuit voltage(V_(OC))of 1.314 V and a fill factor of 83.32%.Moreover,4-ATpHCl modified device exhibited significant improved stability as compared with control *** target device maintained 80%of its initial efficiency after 519 h of maximum power output(MPP)tracking under 1 sun illumination,however,the control device showed a rapid decrease in efficiency after 267 ***,an efficiency of 27.38%of the champion 4-terminal all-perovskite tandem solar cell was achieved by mechanically stacking this wide-bandgap top subcell with a 1.25-eV low-bandgap perovskite bottom subcell.

关键词： Wide-bandgap perovskite Phase segregation lon migration Interface post-treatment All-perovskite tandems

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