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Isogeometric topology optimization based on energy penalization for symmetric structure

Frontiers of Mechanical Engineering 2020年第1期15卷 100-122页

作者： Xianda XIE Shuting WANG Ming YE Zhaohui XIA Wei ZHAO Ning JIANG Manman XU School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Guangzhou Huagong Motor Vehicle Inspection Technology Co. Ltd.Guangzhou 510640China National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510641China

We present an energy penalization method for isogeometric topology optimization using moving morphable components(ITO–MMC),propose an ITO–MMC with an additional bilateral or periodic symmetric constraint for symmetric structures,and then extend the proposed energy penalization method to an ITO–MMC with a symmetric *** energy penalization method can solve the problems of numerical instability and convergence for the ITO–MMC and the ITO–MMC subjected to the structural symmetric constraint with asymmetric *** optimization problems of asymmetric,bilateral symmetric,and periodic symmetric structures are discussed to validate the effectiveness of the proposed energy penalization *** with the conventional ITO–MMC,the energy penalization method for the ITO–MMC can improve the convergence rate from 18.6%to 44.5%for the optimization of the asymmetric *** the ITO–MMC under a bilateral symmetric constraint,the proposed method can reduce the objective value by 5.6%and obtain a final optimized topology that has a clear boundary with decreased *** the ITO–MMC under a periodic symmetric constraint,the proposed energy penalization method can dramatically reduce the number of iterations and obtain a speedup of more than 2.

关键词： topology optimization moving morphable component isogeometric analysis energy penalization method symmetric constraint

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Exceptional strength and ductility in 18Ni300/316 L heterogeneous bionic structures through laser additive manufacturing

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materials Characterization 2025年

作者： Xinge Zhang Minglv Mao Wenquan Wang Jingwei Liang Xudong Liang Zhihui Zhang Zhimin Liang Key Laboratory of Automobile Materials (Ministry of Education) School of Materials Science and Engineering Jilin University No. 5988 Renmin Street Changchun 130022 China Key Laboratory of Bionic Engineering (Ministry of Education) Jilin University Changchun 130022 China Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and Engineering Hebei University of Science and Technology Shijiazhuang 050018 PR China

Compared to single-phase materials, heterogeneous structural materials exhibit significant potential in achieving an excellent combination of strength and ductility. To harness this potential, 18Ni300/316 L layered heterogeneous structural materials were fabricated through a controlled laser direct energy deposition strategy. Samples with a higher content of the relatively softer 316 L exhibited fracture elongation of up to 31.7 %. In contrast, samples with a higher content of the relatively harder 18Ni300 exhibited higher tensile strength, reaching 812 MPa, with only a slight reduction in ductility (28.5 %). The microstructure of the 18Ni300/316 L samples transformed from dendritic, equiaxed grains to columnar grains, consisting of martensite and austenite phases. The austenite grains extended from the 316 L region into the 18Ni300 region, exhibiting characteristics of epitaxial growth. During tensile testing, the “soft” (316 L layer) and “hard” (18Ni300 layer) regions at the interface underwent uneven deformation. The harder region induced normal stress, while the softer region induced back stress, leading to heterogeneous deformation-induced strengthening of the material. The novel implementation of the heterogeneous structure process may provide a new solution for overcoming the trade-off between strength and ductility.

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Insights into Laser Powder Bed Fused Β-Type Titanium Alloy: Investigating Corrosion Behavior and Wear Properties after Post-Heat Treatment

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SSRN 2025年

作者： Luo, Xuan Li, Yuhao Yang, Chao Zhao, Chao Ma, Hongwei Song, Tao Sun, Minghan Liu, Xiaotao Li, Dongdong Li, Ning State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Wuhan430074 China National Engineering Research Center of Near-net-shape Forming for Metallic Materials Guangdong Provincial Key Laboratory for Processing Forming of Advanced Metallic Materials South China University of Technology Guangzhou510640 China Ningbo University China School of Materials Science and Engineering

The systematic evaluation of corrosion resistance and wear behavior represents a critical imperative for advancing biomedical titanium alloys in implant applications. This study systematically examines the corrosion-wear characteristics of laser powder bed fusion (LPBF)-fabricated β-type Ti-34.5Nb-6.9Zr-4.9Ta-1.4Si (TNZTS) alloy after post heat treatment, comparing with LPBF-processed Ti-35Nb-7Zr-5Ta (TNZT) and Ti-6Al-4V counterparts. Electrochemical analysis reveals the TNZTS system's excellent corrosion resistance, stemming primarily from reduced porosity and stabilized passivation film formation. The incorporation of Si effectively addressed the inherent limitation of TNZT alloy in forming defective passivation films under high-potential conditions, thereby enhancing their corrosion resistance. In addition, the TNZTS alloy with hard S2 phase also showed a significant improvement in wear resistance, as manifested by shallower and narrower wear tracks and a lower specific wear rate. This study provides foundational insights into the novel β-type Ti-Nb-Zr-Ta-Si alloy with excellent corrosion resistance and wear properties, positioning it as a promising candidate for load-bearing orthopedic implant applications. © 2025, The Authors. All rights reserved.

关键词： Passivation

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Microstructural evolution and mechanical instability of Mar-M509 superalloy fabricated by laser powder bed fusion under short-term thermal exposure

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materials Science and Engineering: A 2025年 940卷

作者： Cao, Tingwei Chen, Chaoyue Wei, Daixiu Zhao, Ruixin Hou, Yuyang Lu, Lin Yang, Tao Ke, Linda Gong, Wu Kawasaki, Takuro Harjo, Stefanus Shi, Lei Lei, Liming Wang, Jiang Ren, Zhongming State Key Laboratory of Advanced Special Steels School of Materials Science and Engineering Shanghai University Shanghai200444 China Jiangsu Belight Laboratory State Key Laboratory of Advanced Casting Technologies Nanjing University of Science and Technology Nanjing210094 China Shanghai Engineering Research Center of 3D Printing Materials Shanghai Research Institute of Materials Co. Ltd Shanghai200437 China Department of Materials Science and Engineering City University of Hong Kong China Shanghai Engineering Technology Research Center for Near-net Forming of Metal Materials Shanghai Aerospace Precision Machinery Institute Shanghai200444 China J-PARC Center Japan Atomic Energy Agency 2-4 Shirakata Tokai Naka-gun Ibaraki319-1195 Japan AECC Shanghai Commercial Aircraft Engine Manufacturing Co. Ltd. Shanghai201306 China TaiHang Laboratory Chengdu610213 China

The thermal stability of microstructure and mechanical performance is crucial for the industrial application of laser powder bed fusion (LPBF) superalloy components in gas turbines and jet engines. This work investigated the microstructural evolution and strengthening mechanism of LPBF Mar-M509 cobalt-based superalloy before and after thermal exposure at 1200 °C using multi-scale microstructural characterization and in situ neutron diffraction tensile testing. The as-built Mar-M509 superalloy exhibited a heterogeneous microstructural features with coarse columnar and fine equiaxed grains, both containing dendritic and cellular substructures enriched with nanoscale carbides and high-density dislocations. The ultra high strength (1504 ± 4 MPa) of the as-built sample was primarily attributed to dislocation-precipitation synergistic strengthening. After thermal exposure at 1200 °C for 4 h, the dendritic and cellular substructures disappeared and the dislocation density decreased significantly. Meanwhile, Cr, Ta, and other solute elements segregated along fast diffusion channels such as dislocations, stacking faults, and grain boundaries, and combined with the liberated carbon to re-precipitate as coarse M23C6 and MC carbides. The precipitation of microscale M23C6 carbides at the grain boundaries not only weakened the Orowan strengthening mechanism but also reduced the grain boundary strength, resulting in a decrease in the tensile strength to 1192 ± 8 MPa. High-temperature stress rupture testing further revealed microstructural instability in the as-built sample, which adversely affected its stress rupture life. Although the elongation of the sample after thermal exposure decreased from 25.9 % to 10.64 %, its stress rupture life increased from 119:01 h:min to 331 h. This study reveals the microstructural evolution and instability of LPBF Mar-M509 superalloy under high-temperature exposure and the impacts on mechanical properties, which provides critical support for the

关键词： Tensile testing

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Facilitating Charge Utilization via Semi-embedding Cocatalyst Adjacent to the Interfacial Region in Composite Photocatalyst

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SSRN 2025年

作者： Li, Shunfeng Hu, Miao Hu, Chengcai Hu, Zishuai Liu, Yuqi Peng, Weixing Bo, Xin Li, Guanna Wang, Zenglin Li, Rengui Ma, Yi Key Laboratory for Macromolecular Science of Shaanxi Province School of Chemistry &Chemical Engineering Shaanxi Normal University Xi’an710119 China Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and Engineering Hebei University of Science and Technology Shijiazhuang050000 China Biobased Chemistry and Technology Wageningen University Bornse Weilanden 9 Wageningen6708 WG Netherlands State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian116023 China

Converting sunlight into chemical fuels using semiconductor photocatalysts has garnered significant attentions, in which how to maximize the utilization of short-lived, surviving photogenerated charges in surface catalytic reactions is crucial. Herein, we proposed a strategy via semi-embedding cocatalyst adjacent to the interface of composite photocatalyst, to reduce the migration distance of photogenerated charges and maximize the interfacial charge utilization via two migration pathways from both sides. Owing to the partial collapse of MIL-125 and strong interaction between the noble metal and sulphide-containing ions, a ternary composite photocatalyst ZnIn2S4-Pt-TiO2 was constructed via self-assembling of ZnIn2S4 on semi-embedded Pt-TiO2, which exhibits a greatly improved photocatalytic hydrogen evolution under visible light (≥420 nm), showing an order of magnitude higher activity compared with the traditional ZnIn2S4/TiO2 composite. The ZnIn2S4-Pt-TiO2 gives apparent quantum efficiencies of 38%@380 nm, 27%@420 nm and 24%@440 nm for photocatalytic hydrogen production, which surpasses most of the ZnIn2S4-based photocatalysts. DFT results indicate a significant electron transfer from heterojunction interface to the adjacent Pt, which results in strong interaction between Pt and H atoms and guarantees the efficient proton reduction for H2 evolution. This work provides a unique strategy that benefits the interfacial charge transfer and utilization in photocatalysis. © 2025, The Authors. All rights reserved.

关键词： Photocatalytic activity

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Correction to:Tuning dual three-dimensional porous copper/graphite composite to achieve diversified utilization of copper current collector for lithium storage

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Rare Metals 2025年第2期44卷 1409-1409页

作者： Ma Xia Zhang Zhijia Wang Jiamin Sun Shihao Zhang Shaofei Yuan Shen Qiao Zhijun Yu Zhenyang Kang Jianli Li Weijie School of Materials Science and Engineering School of Mechanical EngineeringTiangong University State Key Laboratory of Separation Membrane and Membrane ProcessesTianjin Municipal Key Laboratory of Advanced Fibers and Energy Storage Tianjin 300387 School of Materials Science and Engineering Tianjin University Tianjin 300072 School of Materials Science and Engineering Hebei University of Science & Technology Hebei Key Laboratory of Material Near-Net Forming Technology Shijiazhuang 050018 Institute for Superconducting and Electronic Materials University of Wollongong Australia Wollongong 2522

In the original publication,incomplete Fig.1 has been *** correct version of Fig.1 is provided in this correction.

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Effects of strain paths on the fracture forming limit of high strength structural steel sheets

Effects of strain paths on the fracture forming limit of hig...

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2020 International Conference on Internet of Things, Artificial Intelligence and Mechanical Automation, IoTAIMA 2020

作者： Xu, Teng Xia, Qin-Xiang Qi, Zhen-Jie Wu, Xiao-Yu Ran, Jia-Qi Gong, Feng Guangdong Provincial Key Laboratory of Micro Nano Optomechatronics Engineering College of Mechatronics and Control Engineering Shenzhen University China Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology School of Mechanical and Automotive Engineering South China University of Technology China Shenzhen Key Laboratory of Advanced Manufacturing Technology for MouldandDie College of Mechatronics and Control Engineering Shenzhen University China National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials China

The cruciform two-axial tensile specimen was designed and the two-axial tensile test scheme for different strain paths was developed. The effect of strain paths on the forming limit of high strength structural steel plates was obtained by the DIC method. The results show that for the unidirectional alternating loading test scheme, the equivalent strain of the ultimate strain is less than the sum of the equivalent strains from each step. When the main strain direction of the specimen pre-strain is perpendicular to the final strain path, the forming limit decreases with the increase of the pre-strain. © 2020 Published under licence by IOP Publishing Ltd.

关键词： Strain

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Effect of B Addition on the Formation of Fe-Rich Phases in Al-Si-Fe Alloys

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SSRN 2022年

作者： Song, Dongfu Zhao, Yuliang Jia, Yiwang Huang, Guangyao Zhang, Zhibo Zhou, Nan Li, Xintao Zheng, Kaihong Fu, Yanan Zhang, Weiwen Guangdong Provincial Key Laboratory of Metal Toughening Technology and Application Institute of New Materials Guangdong Academy of Sciences Guangzhou510650 China National Engineering Research Centre of Near-net-shape Forming for Metallic Materials South China University of Technology Guangzhou510641 China Neutron Scattering Technical Engineering Research Centre School of Mechanical Engineering Dongguan University of Technology Dongguan523808 China Jiangxi Universal New Material Technology Co. Ltd Shangrao334499 China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute CAS Shanghai201204 China

Boron (B) is an effective grain refiner in Al-Si alloys, but the modification mechanism of B on the formation and solidification behaviour of Fe-rich phases is still in debate. In this paper, we used in situ synchrotron X-ray radiography, combined with thermodynamics and first-principles calculations, to study the influence of B on the evolution and solidification behaviour of microstructure of Fe-rich phases in Al-7Si-xFe (x=1.2~3.0) alloys. The results showed that B had an excellent influence on the refinement of α-Al grains in Al-7Si-1.2Fe alloys, but it had no obvious effect on the morphology and distribution of Fe-rich phases due to the eutectic reaction to form Al-AlB 2 . B had a certain refining effect on primary Fe-rich phases in Al-Si-Fe alloys with high Fe content (≥2.36 wt.%), but it did not totally prevent the formation of these phases. The results of in situ synchrotron X-ray radiography showed that the addition of B significantly reduced the formation temperature of primary Fe-rich phases. The first-principles calculations showed that the adsorption energy of B on the surface of α-Al 2 O 3 (0001) was significantly higher than that of Fe, which inhibited the nucleation of the primary Fe-rich phase above the Al-AlB 2 eutectic temperature and promoted its supercooling of nucleation. Furthermore, many α-Al nuclei formed during the transition to the Al-AlB 2 eutectic;their subsequent growth hindered the development of the primary iron-rich phase. These were the main reasons for the refinement of the primary Fe-rich phases. The results of this study provide insights for designing recycled Al-Si alloys and fundamental knowledge of Fe-rich phase modification by B addition. © 2022, The Authors. All rights reserved.

关键词： Silicon alloys

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Cover Feature:N-PType Charge Compensatory Synergistic Effect for Schottky and Efficient Photoelectrocatalysis Applications: Doping Mechanism in (Nb/Re)@WS2/Graphene Heterojunctions (Chem. Eur. J. 2/2025)

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Chemistry – A European Journal 2025年第2期31卷

作者： Zhonghao Zhou Wei Qi Zhi Li Li Yang Zhichao Lin Renguo Guan School of Material Science and Engineering Engineering Research Center of Continuous Extrusion Ministry of Education Dalian Jiaotong University Dalian 116028 China School of Materials and Metallurgy University of Science and Technology Liaoning Anshan 114051 China College of Material Engineering Fujian Agriculture and Forestry University Fuzhou 350108 China Key Laboratory of Near-Net Forming of Light Metals of Liaoning Province Dalian Jiaotong University Dalian 116028 China

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Effect of melt holding on morphological evolution and sedimentation behavior of iron-rich intermetallic phases in Al-Si-Fe-Mn-Mg alloy

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Transactions of Nonferrous Metals Society of China 2020年第1期30卷 1-13页

作者： Dong-fu SONG Shun-cheng WANG Yu-liang ZHAO Shu-hong LIU Yong DU Yue-hua KANG Zhi WANG Wei-wen ZHANG National Engineering Research Centre of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China Guangdong Institute of Materials and Processing Guangzhou 510650China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

The effect of the melt holding temperature on the morphological evolution and sedimentation behavior of iron-rich intermetallics in Al-7.0 Si-1.0 Fe-1.2 Mn-0.25 Mg alloy was investigated using an optical microscope,scanning electron microscope and differential thermal *** results show that as the holding temperature decreases,the morphologies of the primary iron-rich phase in matrix change from star-like to polygonal,and the number of the primary phases gradually decreases and disappears at 615°***,the Chinese script phases with small size,high compact and uniform distribution are *** contrast,the primary iron-rich phases in slag transform into a coarser polygonal shape with lower roundness,and some of them have hollow ***,the area fraction of intermetallics and Fe content in the matrix decrease gradually due to the formation and growth of sludge and subsequent natural sedimentation during melt *** the decrease of holding temperature,the main factors hindering the settlement of the primary phases are morphology,size,and density in turn.

关键词： Al-Si alloy melt holding iron-rich intermetallic phases morphological evolution sedimentation behaviour

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