检索结果-内蒙古大学图书馆

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

作者： Li, Chunming Zhang, Feng Yang, Yong Chen, Yunbo Zuo, Lingli Zhang, Yang Chen, Lin State Key Laboratory of Advanced Forming Technology and Equipment Beijing National Innovation Institute of Lightweight Ltd Beijing100083 China Anhui Fenghui Metal Co. Ltd. Fuyang236500 China

ISBN: (纸本)9781728182889

the influence of aging treatment on the microstructure and corrosion resistance of 7××× series aluminum alloy was studied by means of microstructure analysis, energy spectrum analysis, tensile test and intergranular corrosion test. The results show that the tensile strength, yield strength and elongation of alloy after peak-aging (121°C / 24 h) treatment are 605.3 MPa, 501.9 MPa and 8.6%, respectively, but which corrosion resistance is the worst;the strength of over-aged (121°C / 6 h + 177°C / 8 h) is significantly lower than that of peak-aging, but it has highest elongation, reaching 11.9%, besides, its corrosion resistance is the best;the strength of interrupted ageing (121°C / 0.5 h (water cooling) + 65°C / 240 h + 121°C / 24 h) alloy is the highest, and the corrosion resistance is better than those of peak-aging. © 2020 IEEE.

关键词： Corrosion resistance

来源：评论

学校读者我要写书评

暂无评论

Dynamic Modeling of Over-Constrained Parallel Driving Mechanism with Planar Sub-Closed-Chains

SSRN

引用

SSRN 2022年

作者： Huang, Yangyang Zhang, Jinzhu Xiong, Xiaoyan Wang, Rui Liu, Hongfei College of Mechanical and Vehicle Engineering Taiyuan University of Technology Taiyuan030024 China Department of Mechanical Engineering The State Key Laboratory of Tribology Institute of Manufacturing Engineering Tsinghua University Beijing100084 China Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment Ministry of Education Taiyuan030024 China

This paper proposes a novel 4-degree-of-freedom (DOF) parallel driving mechanism (PDM) with sub closed-chains. PDM consists of operating mechanisms, driving mechanisms and connecting joints. First, displacement, velocity and acceleration models of the PDM are established. Then, the Newton-Euler approach is taken to deduce the kinematic formula of each link and the formula of inertial force at the center of mass. At the same time, it remains difficult to solve the equation since the number of equations is less than the number of unknowns. To solve this problem, the decoupling principle of PDM is proposed in this paper. The operating mechanism is decoupled from the driving mechanism at the connecting joints. Further, the screw theory is applied to analyze the cause of over-constraints problems, and 9 deformation coordination equations are introduced. Moreover, a complete dynamic model of the mechanism is obtained. According to the co-simulation with Matlab, Adams and Abaqus, the method is correct and reasonable. At last, a physical prototype is developed to verify the correctness of the dynamics. © 2022, The Authors. All rights reserved.

关键词： Dynamics

来源：评论

学校读者我要写书评

暂无评论

Towards Ultralow Friction or Even Superlubricity in Inconel 718 Tube Drawing Representing Metal forming Under Large-Amplitude Sliding

SSRN

引用

SSRN 2022年

作者： Zhang, Duo Li, Heng Liu, Chongde Zheng, Yuanyang Wang, Zheng Fu, Mingwang State Key Laboratory of Solidification Processing 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 Department of Mechanical Engineering Research Institute for Advanced Manufacturing The Hong Kong PolytechnicUniversity HungHom Kowloon Hong Kong

Friction has a crucial impact in different physical domains and industries. Friction sometimes plays a positive factor to facilitate and promote the happening of various physical behaviors and phenomena, while in most scenarios, it has a negative impact to generate severer wear, damage, fracture of the materials/tools, increasing the need force, consuming more energy, and resulting in higher production cost. In metal forming, friction coefficient mostly falls into the range from 0.1 and 1. When the friction coefficient is reduced to ultralow, even to superlubricity with the friction coefficient smaller than 0.01, the above-described issues and phenomena can be efficiently solved to a large extent. The friction behavior is affected by friction pair (component materials and surface coating), surface state (roughness, lubricant) and boundary conditions (pressure, contact area and sliding amplitude). Large-amplitude sliding of the contact surface occurred frequently in metal forming may result in the change of tribological morphology and complicate the above-listed issues. Thus, reducing friction coefficient and even achieving superlubricity is a critical challenge to be solved in metal forming with large-amplitude sliding. In the study, by using Inconel 718 superalloy tube as case material and, firstly, tube/sheet drawing was firstly designed as a universal method to representing the large-amplitude sliding of contact interface in metal forming. To obtain the friction coefficient under the large-amplitude sliding, ex-situ drawing experiment and finite element model were designed with different contact areas or size effect, pressure, lubricants, surface roughness and surface deposited layer. Secondly, the friction mechanism under the large-amplitude sliding was revealed by in-situ drawing experiments and macro/micro scaled modeling, viz., tube drawing FE model with lubrication pocket and molecular dynamics model. Thirdly, the coupling influence mechanisms of contact are

关键词： Surface roughness

来源：评论

学校读者我要写书评

暂无评论

Modulating dislocation reactions through preferential hydrogen segregation in bcc metals

arXiv

引用

arXiv 2024年

作者： Hou, Jie Peng, Ducheng Kong, Xiang-Shan Deng, Huiqiu Hu, Wangyu Chen, Cheng Song, Jun College of Materials Science and Engineering Hunan University Changsha410082 China State key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Shandong Jinan250061 China School of Physics and Electronics Hunan University Changsha410082 China School of Aeronautics Northwestern Polytechnical University Shaanxi Xi’an710072 China Department of Mining and Materials Engineering McGill University MontrealQCH3A 0C5 Canada

The interaction between dislocations is fundamental to plastic deformation, work hardening, and defect accumulation. While extensive research has focused on the impact of solutes on individual dislocations, how solutes affect dislocation-dislocation reactions remains largely unexplored. Here, using atomistic simulations of iron as a model bcc system, we demonstrate that hydrogen solutes enable two /2 screw dislocations to react and form a edge dislocation junction, a process that is otherwise unfavorable in hydrogen-free environments. This phenomenon arises from the preferential segregation of hydrogen around the dislocation, which reduces the energy of the reaction product. The resulting dislocation demonstrates remarkable stability and transforms into a vacancy-type dislocation loop under strain. These vacancy-type dislocation loops can accumulate during continuous deformation and dislocation reactions, serving as precursors for the initiation of structural damage, such as cracking and blistering. Our findings highlight the pivotal role of hydrogen in dislocation reactions, uncover a novel defect accumulation mechanism crucial for interpreting recent experimental observations, and represent a significant advance in understanding hydrogen-induced damage in bcc metals. Copyright © 2024, The Authors. All rights reserved.

关键词： Screw dislocations

来源：评论

学校读者我要写书评

暂无评论

The effects of v and Mo addition on microstructure and mechanical properties of 60SI2CR spring steel for grinding balls

The effects of v and Mo addition on microstructure and mecha...

引用

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

作者： Zuo, Lingli Pan, Peng Chen, Yunbo Jiang, Qingwei Zhang, Tianxiang Zhang, Yang Qi, Yesi Beijing National Innovation Institute of Lightweight Ltd. State Key Laboratory of Advanced Forming Technology and Equipment Beijing China Yunnan Kungang Wear Resistant Material Science Co. Ltd. Yuxi China

ISBN: (纸本)9781728182889

Effects of V and Mo micro-alloy elements on the microstructure and mechanical properties of 60Si2Cr grinding ball steel were studied by means of optical microscope, scanning electron microscope, tensile test, impact test and Rockwell hardness test. Results show that by adding 0.12wt%Mo to 60Si2Cr grinding ball steel, less cementite can be precipitated from the matrix than adding 0.08wt%V, so that the hardness of wear-resistant steel ball is higher. The addition of V can refine the needle-like martensite structure, which is conducive to the improvement of impact toughness. The best comprehensive mechanical properties can be obtained by adding 0.12wt%Mo and 0.08wt%V simultaneously, with the ultimate tensile strength (UTS) of 2 277.7 MPa, the yield strength (YS) of 1 753 MPa, the near surface hardness (SH) of 62 HRC, the core hardness (CH) of 60.7 HRC, and the impact energy of 54.3 J/cm^2. The results show that the addition of 0.08wt% V and 0.14wt%Mo to 60Si2Cr grinding ball steel can effectively improve the impact toughness and hardness. © 2020 IEEE.

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

Minor pre-tension and aging-induced fine dispersion of precipitates for strength-ductility coordination in Mg-Y-Nd alloys

引用

Journal of Rare Earths 2025年

作者： Yanan Yu Luyi Han Ximan Sun Xiangjian Zhu Dejin Wei Guangchun Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University Jinan 250061 China State key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan 250061 China

Increasing the number density of precipitates is a critical factor in enhancing the strength-ductility balance of metallic materials. This study investigates the precipitation behavior of dislocation-induced precipitates and its impact on the strength-ductility coordination through minor pre-tension applied before aging. Statistical analysis of precipitate size reveals that pre-tension-induced dislocations provide additional nucleation sites, resulting in β′ phase refinement and a more dispersed distribution, which effectively alleviates stress concentration. In contrast, non-pre-tensioned samples exhibit increased grain boundary precipitates and larger PFZs, leading to extensive intergranular fracture. The pre-tension treatment accelerates aging kinetics, significantly reducing prismatic dislocation density after aging. This reduction facilitates β 1 phase nucleation and its linear arrangement along specific prismatic planes. This work systematically examined intra-granular precipitation strengthening induced by minor pre-tension, along with the interaction mechanisms between grain boundary precipitates and PFZs, providing crucial insights for developing high-performance magnesium alloys.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Novel multi-axis differential velocity sideways extrusion process for 3D curved profiles: Feasibility and forming mechanisms studies

引用

International Journal of Machine Tools and Manufacture 2025年

作者： Yutong Sun Junquan Yu Guoqun Zhao Xiqing Ge State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan Shandong 250061 PR China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University Jinan Shandong 250061 PR China

3D curved profiles or extrudates are widely used in industry; however, their flexible manufacturing with very few processing steps remains a great challenge. In this study, a novel extrusion-bending integrated process, termed multi-axis differential velocity sideways extrusion (MX-DVSE), was developed to form controlled 3D curved extrudates within a single operation, and its forming mechanics was clarified by experiments and finite element modelling. The MX-DVSE equipment was set up, and a set of dies was designed to perform a series of experiments in which two pairs of opposing punches were moved at different velocities. During the MX-DVSE process, the superposition of the velocity gradients generated by the four extrusion velocities induces the bending deformation of the extrudates with a controllable bending radius and deflection angle. The bending radius is determined by velocity gradient, velocity gradient ratio, and extrusion ratio. The bending radius decreased with an increase in the deviation of the velocity gradients from 1, reduction in the velocity gradient ratio, and increase in the extrusion ratio. The velocity gradient and velocity gradient ratio can be unified into a proposed indicator, termed the bending radius control factor, which exhibits a monotonic relationship with the bending radius. The deflection angle depends on the extrusion velocity and the velocity gradient. The bending plane of the extrudate was close to the direction of the velocity gradient, which deviated from 1 or the direction of the maximum velocity. This is reflected in another proposed indicator: the deflection angle control factor. The feasibility of the MX-DVSE technique was further verified by considering the specific shape and size of 3D curved extrudates as the forming targets. The experimental results show that MX-DVSE can form 3D curved extrudates with acceptable dimensional accuracy, and the proposed control factors for the bending radius and deflection angle can accurat

关键词：

来源：评论

学校读者我要写书评

暂无评论

MBSE-Based Integration of Superplastic forming Manufacturing Process Information for Customized Products

引用

Processes 2025年第5期13卷 1497-1497页

作者： Xingwei Zhou Wanran Yang Haiyu Guo Shaozong Wang Boya Wang Le Wu Chengyue Xiong Ailing Zou Bo Wang Fanrong Zeng Gongxi Zhou Shijiang Li Liang Hou Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen University Xiamen 361102 China State Key Laboratory of Advanced Forming Technology & Equipment Beijing National Innovation Institute of Lightweight Ltd. Beijing 101407 China

Optimizing superplastic forming (SPF) process parameters is vital for improving production efficiency and addressing the growing complexity of product requirements in high-end manufacturing fields. Current optimization of SPF process parameters focuses on meeting product requirements, often overlooking constraints related to quality indicators, process, and equipment limitations. This paper proposes an optimization approach that integrates SPF manufacturing process information using model-based systems engineering and simulation validation techniques to establish a continuous mapping between product requirements, process parameters, and equipment control parameters. First, SPF is modeled using the systems modeling language to describe the relationships between processes and equipment. Then, the process parameters are extracted via object flow analysis and categorized according to shape and performance control. The key process parameters and impact indicators for meeting customized product requirements are identified using the analytic hierarchy process. Finally, orthogonal experimental design and process simulation are employed to optimize the parameters, with the results mapped onto the physical model to guide the equipment control parameter design. A case study demonstrates its feasibility and effectiveness in meeting customized products.

关键词： model-based systems engineering superplastic forming customized products process parameters

来源：评论

学校读者我要写书评

暂无评论

Enhanced performance study of energy capture ball valve integrated with a new type of torsional impeller

引用

Energy 2025年 330卷

作者： Jinmin Xiong Guangchao Zhang Yudong Xie Shinong Wang Mupeng Bao Yong Wang School of Mechanical Engineering Shandong University Jinan 250061 China Key Laboratory of High-efficiency and Clean Mechanical Manufacture (Shandong University) Ministry of Education Jinan 250061 China State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan 250061 China

In this study, a new impeller with a torsion angle between the middle section and the end face of the blade is proposed, so as to improve the energy capture performance of the energy capture ball valve (integrated impeller in valve), and to be more compatible with the flow regulation performance of the valve. Under the condition of large pipe diameter, the flow regulation and energy capture characteristics of the valve with ordinary impeller and torsional impeller are compared, and the influence mechanism of the torsion angle structure on the performance of the valve is studied. The research shows that the torsional impeller improves the pressure difference between the concave and convex surfaces of the blade, reduces the magnitude and frequency of negative moments during the rotational cycle, and also changes the strength of the vortex at the concave surface of the impeller's driving blade, thereby improving the energy capture efficiency and fluid regulation capacity of the valve. When the blade arc angle is 180°, the valve with 90° torsion angle improves 26.25 % of the output shaft power, 6.8 % of the flow coefficient and 44.3 % of the energy capture efficiency compared with the ordinary impeller ball valve.

关键词： Ball valve Blade arc angle Energy capture Flow regulation Hydraulic turbine Torsion angle

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to “Enhancing the fracture toughness of aerospace-grade carbon fibre/epoxy composites by interlaying surface-activated low-melt polyaryletherketone (LMPAEK) meshes” [Composites Part B 287 (2024) 111824]

引用

Composites Part B: Engineering 2025年

作者： Dong Quan Xuemin Wang Jiaying Pan Yannan Ma Gennaro Scarselli Guoqun Zhao State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan Shandong 250061 China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University Jinan Shandong 250061 China Department of Innovation Engineering University of Salento Italy

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：