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Radial envelope forming mechanism and process design method for cylindrical rings with thin wall and high web ribs

Chinese Journal of Aeronautics 2023年第12期36卷 461-476页

作者： Xinghui HAN Yanlei MIN Wuhao ZHUANG Lin HUA Duanyang TIAN Zushen DENG Ningbo LIU Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong LaboratoryXiangyang 441000China

Cylindrical rings with thin wall and high web ribs(CRTWHWR)are widely used as the key load bearing structures such as rocket body and space station cabin in aerospace ***,it is still difficult to efficiently manufacture CRTWHWR with high performance because of their extreme geometry with thin-walled skins,high web ribs and large *** this paper,a novel radial envelope forming process is put forward to efficiently achieve the plastic forming of CRTWHWR with high ***,the principle of radial envelope forming process is ***,an efficient design method for the tool motion and geometry is proposed based on the reverse envelope principle,i.e.,CRTWHWR is adopted to reversely envelope the tool and thus the tool which does not interfere with CRTWHWR can be efficiently obtained in a single ***,a reasonable 3D FE model of the radial envelope forming process of CRTWHWR is established and the radial envelope forming mechanism of CRTWHWR is comprehensively *** the FE simulation and experiments with material of plastic mud,a typical CRTWHWR with diameter of 300 mm,axial height of 192 mm,the maximum rib height of 25 mm,the minimum rib thickness of 3 mm and skin thickness of 5 mm is radial envelope formed,i.e.,the ratio of the maximum rib height to the minimum rib thickness reaches 8.33,the ratio of the maximum rib height to skin thickness reaches 5 and the ratio of diameter to the minimum rib thickness reaches *** above results verify that the proposed radial envelope forming process has great potentials in efficiently manufacturing CRTWHWR with extreme geometry.

关键词： Radial envelope forming Cylindrical ring with thin wall and high web ribs Forming mechanism FE simulation Tool design

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Effect of key factors on cold orbital forging of a spur bevel gear

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Journal of Central South University 2016年第2期23卷 277-285页

作者：庄武豪董丽颖 School of Materials Science and Engineering Wuhan University of Technology School of Automotive Engineering Hubei Key Laboratory of Advanced Technology for Automotive ComponentsWuhan University of Technology

Cold orbital forging is an advanced spur bevel gear forming technology. Generally, the spur bevel gear in the cold orbital forging process is formed by two steps: the preforming step and the final step. Due to the great importance of the final step to gear forming and its complication with interactive factors, this work aims at examining the influence of key factors on the final step in cold orbital forging of a spur bevel gear. Using the finite element(FE) method and control variate method, the influence rules of four key factors, rotation velocity of the upper tool, n, feeding velocity of the lower tool, v, tilted angle of the upper tool, γ, friction factor between the tools and the billet, m, on the geometry and the deformation inhomogeneity of the cold orbital forged gear are thoroughly clarified. The research results show that the flash becomes more homogeneous with increasing v, increasing m, decreasing n or decreasing γ. And the deformation of the gear becomes more homogeneous with increasing v, decreasing n or decreasing γ. Finally, a corresponding experiment is conducted, which verifies the accuracy of FE simulation conclusions.

关键词： cold orbital forging FE modeling key factors spur bevel gears

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Effect of Prior Cold Deformation on the Stability of Retained Austenite in GCr15 Bearing Steel

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Acta Metallurgica Sinica(English Letters) 2019年第1期32卷 107-115页

作者： Feng Wang Dong-Sheng Qian Xiao-Hui Lu School of Materials Science and Engineering Wuhan University of Technology Hubei Key Laboratory of Advanced Technology for Automotive Components School of Automotive Engineering Wuhan University of Technology

In this work, the effect of prior cold deformation on the stability of retained austenite in GCr15 bearing steel was investigated after quenching and tempering treatment. The thermal stability was evaluated by calculating thermal activation energy for decomposition of retained austenite using differential scanning calorimeter. The mechanical stability was investigated according to the strain-induced martensitic transformation behavior of retained austenite under the standard compression testing. It is found that the prior cold deformation not only accelerates the carbide dissolution during the austenitization process but also contributes to the carbon partitioning in the tempering stage due to the higher density of phase boundaries, which results in the improvement of the thermal stability of retained austenite. Due to the enhanced carbide dissolution, the higher carbon content in the prior austenite will intensify the isotropic strain of martensitic transformation. As a consequence, the film-like retained austenite is likely to form under a higher hydrostatic pressure and thus shows a higher mechanical stability. Additionally, it is noteworthy that the benefits of the prior cold deformation to the stability of retained austenite would be saturated when the cold deformation degree is larger than 40%.

关键词： GCr15 bearing steel Prior cold deformation Retained austenite stability

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Microstructural evolution of GCr15 steel during austenitizing and quenching considering C and Cr content

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Journal of Central South University 2016年第10期23卷 2492-2499页

作者：刘青龙钱东升魏文婷 School of Materials Science and Engineering Wuhan University of Technology Hubei Key Laboratory of Advanced Technology for Automotive Components School of Automotive Engineering Wuhan University of Technology

Microstructural evolution of GCr15 steels with different C and Cr contents during austenitizing and quenching was studied. Thermodynamic analysis of cementite dissolution was implied to obtain the critical temperature. The coordination number x in Fe_xCr_(3-x)C and the volume fraction of undissolved cementite were computed according to element conservation and equilibrium phase diagram. The M_S(martensite transformation temperature) was calculated by using empirical formula. The retained austenite content was calculated with further consideration of quenching temperature. The results showed that the coordination number and the undissolved cementite content were promoted by the austenitizing temperature and carbon content of the steel. Increasing Cr element reduced the coordination ***15 steels with different components had nearly the same M_S when austenitization at 830 °C to 860 °C. The interaction of C and Cr complicated the evolution of M_S and retained austenite content. The results were in good agreement with the literature, which could guide to obtain specified retained austenite and/or carbides.

关键词： GCr15 steel austenitization quenching thermodynamic calculation kinetics

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Strength-plasticity matching regulation of cold rotary forged Al5A06 sheets by annealing treatment and its influence on fatigue property

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Journal of Materials Science & technology 2024年第25期192卷 123-148页

作者： Xuan Hu Xinghui Han Lin Hua Fang Chai Wuhao Zhuang Fangyan Zheng Fei Yin Xiaokai Wang Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070PR China Hubei Longzhong Laboratory Xiangyang 441000PR China

Al5A06 sheets by large cold plastic deformation usually have high strength but low plasticity,*** strength-plasticity matching,which may lead to their poor fatigue *** this study,annealing treat-ments are applied on cold rotary forged Al5A06 sheets to regulate strength-plasticity matching and im-prove fatigue *** microstructures,tensile mechanical properties and fatigue properties un-der different annealing parameters were *** abnormal grain growth mechanism of cold rotary forged Al5A06 sheets during 300℃ annealing treatment was investigated,and the fatigue failure mech-anism of Al5A06 sheets with different annealing temperatures was also *** abnormal grain growth during 300℃ annealing treatment is mainly due to the asynchronous recrystallization behavior with low recrystallization driving force,which leads to the early recrystallized regions directly absorb-ing adjacent grains along134crystal *** cold rotary forged Al5A06 sheets after 250℃-2 h annealing treatment exhibit the best fatigue property,which is mainly because the optimum strength-plasticity matching brings about coordinate plastic deformation throughout most grains,and the effective dislocation movement between adjacent grains can delay the appearance of strain localization and ac-commodate continuous fatigue cyclic loading.

关键词： Al5A06 sheets Cold rotary forging Annealing treatment Strength-plasticity matching Fatigue property

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Characteristic of involute slope modification of asymmetric spur gear

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Journal of Central South University 2015年第5期22卷 1676-1684页

作者：邓小禾华林韩星会 School of Automotive Engineering Hubei Key Laboratory of Advanced Technology of Automotive PartsWuhan University of Technology

The meshing characteristic of asymmetric involute spur gear was studied, the equations of the geometric shape of the asymmetric gear for both sides were deduced, and the equations of contact ratio and the key points of contact were also ***, an involute slope modification method considering the effects of static transmission errors was proposed based on the meshing properties. The characteristic of the involute slope modification was analyzed by changing different modification *** mesh stiffness and synthetic mesh stiffness of unmodified and modified asymmetric spur gears were investigated. Furthermore,the spectrums of synthetic mesh stiffness under different modification parameters were compared. Research results showed that the modification parameters influence the meshing performance of gear pairs, and the proposed modification method was feasible to improve the transmission performance of gear pairs with appropriate modification parameters.

关键词： asymmetric gears involute slope modification synthetic mesh stiffness

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TFM imaging of aeroengine casing ring forgings with curved surfaces using acoustic field threshold segmentation and vector coherence factor

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Chinese Journal of Aeronautics 2022年第11期35卷 401-415页

作者： Shanyue GUAN Xiaokai WANG Lin HUA Yixuan LI Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China

The aeroengine casing ring forgings have complex cross-section shapes,when the conventional ultrasonic or phased array is applied to detect such curved surfaces,the inspection images always have low resolution and even artifacts due to the distortion of the wave *** this article,taking a type of aeroengine casing ring forging as an example,the Total Focusing Method(TFM)algorithms for curved surfaces are ***,the Acoustic Field Threshold Segmentation(AFTS)algorithm is proposed to reduce background noise and data ***,the Vector Coherence Factor(VCF)is adopted to improve the lateral resolution of the TFM ***,a series of 0.8 mm diameter Side-Drilled Holes(SDHs)are machined below convex and concave surfaces of the *** quantitative comparison of the detection images using the conventional TFM,AFTS-TFM,VCF-TFM,and AFTS-VCF-TFM is implemented in terms of data volume,imaging Signal-to-Noise Ratio(SNR),and defect echo *** results show that compared with conventional TFM,the data volume of AFTS-VCF-TFM algorithm for convex and concave is decreased by 32.39%and 73.40%,***,the average SNR of the AFTS-VCF-TFM is gained up to 40.0 dB,while the average 6 dB-drop echo width of defects is reduced to 0.74 mm.

关键词： Aeroengine casing Acoustic Field Threshold Segmentation(AFTS) Curved surfaces Total Focusing Method(TFM) Vector Coherence Factor(VCF)

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One-pot room-temperature synthesis of CsPbBr3/SiO2 nanocrystals with improved stability for white light-emitting diodes

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The European Physical Journal Special Topics 2025年 1-10页

作者： Zhang, Yu Wen, Yunli Dai, Yuxiang Li, Guishun Yun, Junqiang Jing, Chengbin Hubei Key Laboratory of Energy Storage and Power Battery School of Optoelectronic Engineering School of New Energy Hubei University of Automotive Technology Shiyan People’s Republic of China School of Physics and Electronic Information Jiangsu Second Normal University Nanjing China Beijing Tianhe Xinjin Hui Agricultural Technology Co. Ltd. Beijing China Engineering Research Center for Nanophotonics and Advanced Instrument of Ministry of Education Key Laboratory of Polar Materials and Devices of Ministry of Education School of Physics and Electronic Science East China Normal University Shanghai China

The susceptibility to optical instability of perovskite nanocrystals (NCs) under ambient conditions is a serious hindrance for practical applications. The conventional SiO2 coating method for enhancing stability suffered from long reaction times and complicated preparation procedures. In this study, a facile and convenient room-temperature one-pot approach was developed to fabricate CsPbBr3/SiO2 NCs, which involves the addition of tetramethoxysilane (TMOS) in advance. Owing to surface passivation, the PLQY of the CsPbBr3/SiO2 NCs increased to 90% from 70% of the primitive CsPbBr3 NCs. The SiO2 layer formed by the TMOS hydrolysis and condensation reactions also protect the CsPbBr3 NCs from external environment stimuli. Compared with the pristine CsPbBr3 NCs, the air stability, structural stability, polar solvent resistance, thermal stability, and UV resistance stability of the CsPbBr3/SiO2 NCs are markedly enhanced. Also, the CsPbBr3/SiO2 NCs can be used as green phosphors for white light-emitting diode (WLED), which exhibits a luminous efficiency of 40 lm/W.

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Tribological Performance Improvement of Bearing Steel GCr15 by an Alternating Magnetic Treatment

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Acta Metallurgica Sinica(English Letters) 2017年第10期30卷 957-964页

作者： Yan-Li Song Cheng Yu Xia Miao Xing-Hui Han Dong-Sheng Qian Xu Chen Hubei Key Laboratory of Advanced Technology of Automotive Parts Wuhan University of Technology Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology School of Materials Science and Engineering Wuhan University of Technology

This paper discusses the tribological performance of the bearing steel GCr15 treated by an alternating magnetic field. The wear test results showed that the average of wear mass losses decreased by nearly 80% after the magnetic treatment, compared to those before the magnetic treatment. The micro-hardness and microstructures（i.e., grain size,carbide morphology and dislocation distribution） before and after the magnetic treatment were experimentally investigated,and the mechanism of the tribological performance improvement of the bearing steel GCr15 due to the magnetic treatment was then revealed based on the above results.

关键词： Tribological performance Magnetic treatment Bearing steel

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An innovative constraining ring rolling process for manufacturing conical rings with thin sterna and high ribs

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Chinese Journal of Aeronautics 2022年第8期35卷 324-339页

作者： Duanyang TIAN Xinghui HAN Lin HUA Xuan HU Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070 China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China

Conical rings with thin sterna and high ribs(CRTSHR)are key bearing-load parts of aerospace equipment,which are required to be manufactured with high performance and *** ring rolling is the most preferred method for manufacturing high-performance ring parts,but it can hardly achieve the forming of CRTSHR due to the extreme geometry of *** solve this difficulty,an innovative constraining ring rolling process(CRR)is proposed in this paper to manufacture *** evaluate the proposed CRR and reveal its deformation behaviors,a thermomechanical coupled FE model for CRR of CRTSHR is ***,the experiment for CRR of CRTSHR is performed on a modified ring rolling machine,which proves that CRR of CRTSHR is feasible and the established FE model is *** on the reliable FE model,the metal flow mode in deformed CRTSHR is analyzed,and the deformation characteristics such as the stress state,strain distribution and the evolution of power parameters in CRR of CRTSHR are ***,the influences of key parameters such as the friction factor between ring and molds,the diameter of idle roll and the feed velocity of idle roll on CRR of CRTSHR are investigated by FE simulation.

关键词： Conical rings with thin sterna and high ribs Deformation characteristics FE simulation Metal flow Ring rolling

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