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forming Parameter Optimization based on Kriging Model and Genetic Algorithm

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Forming Parameter Optimization based on Kriging Model and Ge...

IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Junxiong Tang Dongdong You Fenglei Li Yong Cheng National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials Guangdong China Guangdong Key Laboratory for Advanced Metallic Materials Processing Guangdong China Beijing Qingtai Data Technology Co. Ltd. Beijing China

When optimizing the processing parameters for hydraulic forming of sheet metal, improving the process parameters based on actual experiments will increase costs, while finite element simulation will lengthen the design cycle. This study proposes a feasible solution by using a Kriging predictive surrogate model to replace the time-consuming finite element model and combining it with multi-objective genetic algorithm for parameter optimization. The optimal process parameters obtained from the simulation validation of finite element analysis prove the feasibility of this solution. This integrated approach of using machine learning and optimization algorithms is practical and promising for improving efficiency and reducing costs in the manufacturing industry.

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Study on the Influence of Printhead Intake Velocity on Pressure of Sand Mold 3D Printer 5

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Study on the Influence of Printhead Intake Velocity on Press...

2021 5th International Conference on Fluid Mechanics and Industrial Applications, FMIA 2021

作者： Shi, Haoming Shan, Zhongde Guo, Zhi Yan, Dandan State Key Laboratory of Advanced Forming Technology and Equipment Academy of Machinery Science and Technology Group Co.Ltd Beijing China Nanjing University of Aeronautics and Astronautics Jiangsu Nanjing China School of Mechanical Engineering University of Science AndTechnology Beijing Beijing China

To achieve the precise forming of sand mold for 3D printing, the relationship between the printhead intake and the pressure fluctuation in the printhead during startup and printing of sand mold 3D printer was studied, and the relationship between the two and the causes of pressure fluctuation is analyzed. With the help of computational fluid dynamics and Fluent software, the internal flow model at a single nozzle is established, and the ink flow under 10 groups of different inlet velocities is simulated to obtain the flow contour and pressure fluctuation values. Combined with the small-channel gas-liquid flow pattern, the relationship among the air intake velocity and the pressure fluctuation and the reasons for the pressure fluctuation are analyzed. The results show that with the increase of intake velocities, the pressure fluctuation amplitude increases. In addition, the disturbance degree of gas-liquid interface wave leads to the difference of pressure fluctuation amplitude as the gas-liquid flow pattern changing. The simulation results agree with the experiments. Therefore, according to the relationship between the intake velocity and the pressure fluctuation amplitude, the stability of the printing system can be improved by limiting the speed ratio of supply pump and return pump. © Published under licence by IOP Publishing Ltd.

关键词： Flow patterns

Enhanced Tribological Properties of Ti-6al-4v-Xcu Alloys Fabricated Through Laser Powder Bed Fusion Under Dry Friction Conditions

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SSRN 2024年

作者： Wang, Chenchen Wang, Yuan Peng, Peng Wang, Jun Wang, Jiao Han, Sheng Ju, Jiang School of Chemical and Environmental Engineering Collaborative Innovation Center of Fragrance Flavour and Cosmetics Shanghai Institute of Technology Shanghai China Hong Kong Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming Shanghai Jiao Tong University Shanghai China Hangzhou Medical College Zhejiang Hangzhou China

Ti6Al4V alloy finds extensive use in aerospace, automotive, and other industries. However, its surface has low wear resistance, limiting its practical applications. This study developed a novel Ti-6Al-4V-xCu alloy using laser powder bed fusion. The effects of Cu content on the microstructure, microhardness, and friction performance of Ti-6Al-4V-xCu alloys were systematically examined. The findings showed that Ti-6Al-4V-1.5Cu and Ti-6Al-4V-4.5Cu alloys have a microstructure consisting of α´ phase and Cu-rich β phase. While the microstructure of Ti-6Al-4V-7.5Cu includes α´+Cu-rich β phase+nano Ti2Cu. The results demonstrated that increased Cu content in Ti-6Al-4V alloy significantly improves microhardness and tribological performance due to solid solution strengthening, grain refinement, and precipitation strengthening. The Ti-6Al-4V-7.5Cu alloy has been a promising candidate for industrial applications. © 2024, The Authors. All rights reserved.

关键词： Microstructure

High-Performance Thermal Interface Material with A Radial Filler Skeleton

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High-Performance Thermal Interface Material with A Radial Fi...

International Conference on (ICEPT) Electronic Packaging technology

作者： Jingjing Zhang Daoqing Liu Jianhui Zeng Xiaoliang Zeng Jian-Bin Xu Yimin Yao Rong Sun Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China Nano Science and Technology Institute University of Science and Technology of China Suzhou China Guangdong Provincial Key Laboratory of New Metal Materials Preparation and Forming South China University of Technology Guangzhou China Department of Electronics Engineering The Chinese University of Hong Kong Hong Kong China

Thermal Interface Materials (TIMs) are utilized in diverse electronic devices to optimize heat dissipation. They effectively enhance cooling efficiency, diminish temperature, and extend device longevity. Among the different types of TIMs, polymer-based composite materials represent a fundamental category that offers numerous advantages, including enhanced thermal performance, mechanical stability, and ease of application. The incorporation of fillers augments the heat dissipation capabilities of the composite material by facilitating efficient heat transfer from the heat source to the surrounding cooler environment. This article outlines the fabrication process of a three-dimensional, lightweight, and mechanically robust radial-oriented silicon carbide (SiC) framework through the utilization of freeze casting technique. The resulting framework exhibits a precisely oriented arrangement of thermal channels. Subsequently, paraffin wax (PA) is infused into the framework and subjected to curing, resulting in the formation of a SiC/PA composite material. The radial SiC/PA composite material exhibits a remarkable maximum thermal conductivity of 1.46 W/(m·K), achieved with a mere filler content of 1.77 vol%. This thermal conductivity surpasses that of pure PA matrix by a significant margin, showing an enhancement of 287.69%. Furthermore, the composite material outperforms other similar three-dimensional filler frameworks in terms of thermal conductivity. By manipulating the framework structure and modulating the phonon transmission pathway, the composite material effectively maximizes its inherent thermal conductivity even at low filler content.

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Experimental and Simulation Study of Heat Transfer and Flow in Molten Pool During Single Layer Multi-Pass Deposition Process

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SSRN 2024年

作者： Huang, Wenhao Zhong, Haihui Wu, Na Jia, Yazhou Sun, Shiqi Li, Xiaoxu College of Mechanical and Electrical Engineering Wenzhou University Wenzhou China School of Mechanical-Electronic and Vehicle Engineering Beijing University of Civil Engineering and Architecture Beijng China College of Materials Engineering North China Institute of Aerospace Engineering Langfang China State Key Laboratory of Advanced Forming Technology and Equipment China Academy of MachineryScience & Technology Beijing China

Laser wire additive manufacturing is widely used in aerospace, space and other fields due to the advantages of high material utilization. In the additive process, the re-melting and fusion of the current pass with the previous pass is involved in order to obtain a deposited part with a flat surface, and the overlap rate greatly affects the formation of multiple passes. And the heat transfer and flow behavior of the molten pool plays a crucial role in the formation of components. Due to the limited understanding of the heat transfer process and kinetic behavior inside the molten pool through experiments, it is especially difficult to study the fluid dynamics inside the molten pool. Therefore, this paper establishes a three-dimensional transient numerical model for laser wire additive manufacturing of 5A06 aluminum alloy to study the heat transfer and flow behavior of the molten pool in the single-layer multi-pass additive process of laser wire additive manufacturing. On this basis, we analyze the changing law of the temperature field and flow field of the molten pool in the process of additive manufacturing, investigate the influence of the heat transfer and internal flow pattern of the molten pool on the deposition geometry, take the optimal lap rate range as a reference, carry out the determination of the more accurate lap rate, and finally analyze the range of the optimal lap rate according to the geometric flatness model. © 2024, The Authors. All rights reserved.

关键词： 3D printing

Conjugated Small Molecule Crystals as A Coupling Layer Between Carbon-based Thermal Interface Materials and Heat Sink

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Conjugated Small Molecule Crystals as A Coupling Layer Betwe...

International Conference on (ICEPT) Electronic Packaging technology

作者： Daoqing Liu Jingjing Zhang Jianhui Zeng Rong Sun Jian-Bin Xu Yimin Yao Xiaoliang Zeng Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China Nano Science and Technology Institute University of Science and Technology of China Suzhou China Guangdong Provincial Key Laboratory of New Metal Materials Preparation and Forming South China University of Technology Guangzhou China Department of Electronics Engineering The Chinese University of Hong Kong Hong Kong China

Carbon-based thermal interface materials (TIMs) play a crucial role in maintaining the performance and reliability of electronic devices by improving their thermal management capabilities. Previous researchers have done a lot of work around improving the thermal conductivity of carbon-based TIMs themselves. However, as the thickness of thermal interface materials used has gradually decreased, researchers have gradually realized that the main bottleneck of heat transfer lies in reducing the interface thermal resistance between the carbon-based TIMs and the encapsulating shell or metal heat sink. In this work, we investigate the mechanism by which organic conjugated small molecule crystals reduce the interfacial thermal contact resistance between carbon-based TIMs and copper heat sink. By modulating the orientation of the organic conjugated small molecules, which have a π-π conjugated structure and a certain electron mobility, we have constructed a heat transfer channel at the interface, significantly enhancing the interfacial heat transfer and improving the overall heat dissipation performance of the device.

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Calculation of the Crss Ratios of Ti80 Alloy and its Application in Accurate Simulation of Texture in Pilger Cold Rolling

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SSRN 2023年

作者： He, Shengtong Zeng, Weidong Zhao, Zibo Zhou, Dadi Xu, Jianwei State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi’an710072 China Defense Technologies Innovation Center of Precision Forging and Ring Rolling School of Materials Science and Engineering Northwestern Polytechnical University Xi’an710072 China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical University Xi’an710072 China Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China

The accurate critical resolved shear stress (CRSS) ratios of different slip systems and deformation history are vital for the texture simulation and controlling for Ti80 alloy pipe during Pilger cold rolling process. This study proposed a comprehensive framework for determining these parameters. A method to calculate the CRSS ratio based on the statistics of activated slip systems was proposed, which could effectively eliminate the error of activated slip systems proportion caused by microtexture. No twinning was observed in the deformation of Ti80 alloy, and the activated slip systems of {0002}, {10[[EQUATION]]0}, {10[[EQUATION]]1} and {11[[EQUATION]]2} were observed through uniaxial in-situ tensile test combined with EBSD at room temperature. And the CRSS ratio of Ti80 alloy has been calculated approximately as τBasal: τPrism: τPyram: τPyram=1:0.8:3.5:6. Based on visco-plastic self-consistent (VPSC) model and the calculated CRSS, the texture with shear strain and without shear strain was simulated respectively in the Pilger cold rolling process. Meanwhile, the mechanism of texture formation was analyzed. The texture component was [0001] ‖ TD, and [11-20]‖ AD when the traditional velocity gradient neglecting shear strain was adopted in simulation. However, the shear strain in ZR direction would cause the texture to rotate 30 ° around the [0001] axis. Compared with that only considering the velocity gradient in the normal strain direction, the rolling texture can be more accurately predicted when considering the history of velocity gradient in all directions. © 2023, The Authors. All rights reserved.

关键词： Textures

Analytical and Experimental Studies of the Improved Conductance-Stability and Stretchability of the Liquid Metal-Embedded Composites Based on a Novel Continuous Annular-Shaped Branch Channels

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SSRN 2023年

作者： Li, Jing Wang, Xi Guo, Shu Chen, Shuang Luo, Yiwen Zhao, Shiyan School of Mechanical Engineering Hubei Modern Manufacturing Quality Engineering Key Laboratory Hubei University of Technology Hubei Wuhan430068 China School of Mechanical and Electrical Engineering University of Electronic Science and Technology of China Sichuan Chengdu611731 China School of Vehicle and Energy Yanshan University Hebei Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao066004 China

Stretchable and conductance-stable composites are critical for progress in flexible electronics. Tremendous efforts have focused on engineering electrical conductors from liquid metal-embedded elastomers. While these elastomers enable elastic compliance and deformability, the embedded liquid metal is vulnerable to puncture that cause undesired electrical failure, and most of the conductive elastomers are strain sensitive with degenerative conductance upon deformations. Here, we combined analytical and numerical analyses with experimental studies to investigate effects of the innovatively designed continuous annular-shaped branch channels, inspired by the Tesla valve, on the performances of the LM-embedded conductive composite. Theoretically, in the process of mechanical deformations, the as-proposed continuous annular-shaped architecture can dissipate the pressure energy of the fluidic LM to enhance the fracture toughness of the composite, while the LM flow could be accelerated as the deformation was removed to maintain the percolated conductive path, leading to excellent conductive stability. Experimentally, the as-fabricated composite conductor with continuous annular-shaped branch channels can be stretched up to ~80% (more than two times higher than conventional LM-embedded composite), and upon fully activating the conductive pathway, a very high conductivity of ~4×104 S·m-1 and conductance change of less than 2% under varied deformations, including stretching, flexing, twisting and compressing, are realized. It is believed that this novel design strategy will extend the understanding and application opportunities of LM as functional materials in the development of flexible electronics. © 2023, The Authors. All rights reserved.

关键词： Liquid metals

Calculation of the Crss Ratios of Ti80 Alloy and its Application in Accurate Simulation of Texture in Pilger Cold Rolling

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SSRN 2023年

作者： He, Shengtong Zeng, Weidong Zhao, Zibo Xu, Jianwei Zhou, Dadi State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'An710072 China Defense Technologies Innovation Center of Precision Forging and Ring Rolling School of Materials Science and Engineering Northwestern Polytechnical University Xi'An710072 China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical University Xi'An710072 China Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China

The accurate critical resolved shear stress (CRSS) ratios of different slip systems and deformation history are vital for the texture simulation and controlling for Ti80 alloy pipe during Pilger cold rolling process. In this work, a method to calculate the CRSS ratio based on the statistics of activated slip systems was proposed, which could effectively eliminate the error of activated slip systems proportion caused by texture. No twinning was observed in the deformation of Ti80 alloy, and the activated slip systems of {0002}, {100}, {101} and {112} were observed through uniaxial in-situ tensile test combined with EBSD at room temperature. And the CRSS ratio of Ti80 alloy has been calculated as τBasal: τPrism: τPyram: τPyram=1:0.8:3.5:6. Based on visco-plastic self-consistent (VPSC) model and the calculated CRSS, the texture with shear strain and without shear strain was simulated respectively in the Pilger cold rolling process. The texture component was [0001] ‖ TD, and ‖ AD when the traditional velocity gradient neglecting shear strain was adopted in simulation. However, the shear strain in ZR direction would cause the texture to rotate 30 ° around the [0001] axis. Compared with that only considering the velocity gradient in the normal strain direction, the rolling texture can be more accurately predicted when considering the history of velocity gradient in all directions. © 2023, The Authors. All rights reserved.

关键词： Textures