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Heat treatment and granule medium internal highpressure forming of AA6061 tube

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Journal of Central South University 2017年第5期24卷 1040-1049页

作者： BI Jiang zhao chang-cai BI Meng-meng DU Bing CHEN Xiao-hua DONG Guo-jiang Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education of China Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China College of Vehicles and Energy Yanshan UniversityQinhuangdao 066004China

The new forming process of AA6061 alloy tube, including solution treatment, granule medium internal high-pressure forming and aging treatment, was developed. The AA6061 alloy tube via heat treatment satisfied the forming requirement, and the granule medium internal high pressure forming method for AA6061 alloy tube was also realized by using convenient implementation with low requirement of equipment and flexible design of product. At a solution temperature of 560℃ and time of 120 min, the elongation of the AA6061 extruded tube increases by 300% and the strength and the hardness dramatically decrease too. Therefore, the AA6061 alloy tube meets the requirement of internal high-pressure forming because of the improvement of formability. The experiments shows that the strength and hardness of AA6061 alloy workpiece recover to that of the as-received alloy at an aging temperature of 180℃ and time of 360 min, and the strength of AA6061 alloy workpiece is equal to the base alloy. The typical parts of convex ring tube, stepped shaft tube and hexagonal tube were successfully produced in lab by using the present forming method. The forming tests show that the maximum expansion ratio(MER) of the AA6061 extruded tube increases by 25.5% and the material properties of formed AA6061 alloy tube reached the performance of as-received alloy.

关键词： aluminum alloy tube solution treatment aging treatment granule medium internal high pressure forming

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ZC型液压缸整体联解法

塑性工程学报 2001年第1期8卷 66-69页

作者：赵长财燕山大学 066004

本文提出了 ZC型液压缸的整体联解法。该计算方法不受βL的限制 ,适用范围广 ,完善了 ZC型液压缸的计算理论 ,进行了有限元对比验算。

关键词： ZC型液压缸整体联解法弹性法兰有限元

对汉语负面排他标记来源的再探讨——以中古译经文献为中心

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古汉语研究 2020年第4期 58-70,127页

作者：赵长才中国社会科学院语言研究所/中国社会科学院大学文学院北京100872

本文以中古汉语译经文献为主(兼及本土文献)对汉语"除舍"类负面排他标记的来源、在中古时期的使用情况以及一些相关的具体问题,做进一步的探讨,认为佛经传入之前汉语已经存在负面排他范畴,使用的标记形式为"自(非)",而"除舍"类负面排他... 详细信息

本文以中古汉语译经文献为主(兼及本土文献)对汉语"除舍"类负面排他标记的来源、在中古时期的使用情况以及一些相关的具体问题,做进一步的探讨,认为佛经传入之前汉语已经存在负面排他范畴,使用的标记形式为"自(非)",而"除舍"类负面排他标记虽然在东汉译经中已有萌芽,但主要是在魏晋以后才逐步发展起来的。"除舍"类负面排他标记的产生主要是汉语"除舍"义动词自身语义演变的结果,佛经翻译以其口语性强的优势起到了推动作用。中古时期"除"的追加用法也已经产生,而非此前学者们认为的唐宋以后才产生。至于追加用法产生的途径,显然是由其表排他的用法自然引申而来的,而非经由对反问句的重新分析才产生。

关键词： “除舍”类负面排他标记中古汉语汉译佛经语义演变

Research on technological parameters of pressure forming with hot granule medium on AA7075 sheet

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Journal of Central South University 2016年第4期23卷 765-777页

作者：董国疆赵长财赵建培押媛媛曹秒艳 College of Vehicles and Energy Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education (Yanshan University)

Hot granule medium pressure forming （HGMF） process is a new process in which granule medium replaces the medium in existing flexible-die hot forming process, such as liquids, gases or viscous medium. Hot forming of light alloy sheet parts can be realized based on the properties of granule medium, such as withstanding high temperature and pressure, filling well, sealing and loading easily. In this work, the forming of AA7075 cylindrical parts by HGMF process is taken as an example to establish the constitutive relation and forming limit diagram （FLD） of AA7075 sheet which is related to temperature by hot uniaxial tensile test of sheet metal. Based on the assumption that granule medium is applied to extended Drucker-Prager linear material model, the finite element model of HGMF process is established and the effect of technological parameters, such as forming temperature, blank-holder gap and drawing ratio, on the sheet metal formability, is studied. The limit drawing ratio curve of AA7075 cylindrical parts at forming temperature of 175-300 ℃ is obtained by HGMF process test, and the limit drawing ratio reaches the maximum value of 1.71 at 250 ℃. The results of numerical simulation are consistent with the results of process test, and the forming force, distribution of wall thichness and form of instability are predicted correctly, which provides reference for the application of HGMF process.

关键词： granule medium aluminum alloy sheet drawing hot forming forming limit diagram

Stress-strain analysis on AA7075 cylindrical parts during hot granule medium pressure forming

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Journal of Central South University 2016年第11期23卷 2845-2857页

作者：董国疆杨卓云赵建培赵长财曹秒艳 College of Vehicles and Energy Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education of China (Yanshan University) Qinhuangdao 066004 China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University Qinhuangdao 066004 China

Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the characteristic of granule medium that seals and loads easily, the technology provides a new method to realize the hot deep-drawing forming on high strength aluminum alloy sheet. Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analysis is conducted for the areas, such as the flange area, force-transfer area and free deforming area, of cylindrical parts deep-drawn by HGMF technology, and the function relation of forming pressure is obtained under the condition of nonuniform distribution of internal pressure. The comparison between theoretical result and experimental data shows that larger deviation occurs in the middle and later period of forming process, and the maximum theoretical forming force is less than the experimental value by 24.6%. The variation tendency of the theoretical thickness curve is close to the practical situation, and the theoretical value basically agrees well with experimental value in the flange area and the top area of spherical cap which is in the free deforming area.

关键词： granule medium aluminum alloy sheet deep-drawing hot forming limit drawing ratio

Frictional characteristics of granular system under high pressure

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Journal of Central South University 2016年第5期23卷 1132-1141页

作者：曹秒艳彭雅新赵长财董国疆杜冰 national engineering research center for equipment and technology of cold strip rolling(yanshan university) Qinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education of China(Yanshan University) Qinhuangdao 066004China College of Vehicles and Energy Yanshan UniversityQinhuangdao 066004China

In order to reveal the force transmission features of the granules in the solid granule medium forming(SGMF) technology,the frictional characteristics of the non-metallic granule medium(NGM) under high pressure were investigated by tests and *** the relevant changing curves of the internal friction coefficient of the granular system under different normal pressures were obtained by self-designed shear *** the granule volume compression test,the accurate discrete element simulation parameters were obtained,based on this,the discrete element method(DEM) was adopted to reveal the evolution law of the NGM granules movement in the sample shear process from the microscopic *** on the DEM,the influence of granule diameter,surface friction coefficient,normal pressure and shear velocity on the internal friction coefficient of the granular system were *** the parameters were conducted to be dimensionless by introducing the inertia ***,the expression showing power-law relationship of inertia coefficient,surface friction coefficient and internal friction coefficient is obtained.

关键词： granule friction coefficient discrete element method inertia coefficient

Structure parameters and function of hydraulic elastic bulging roller

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中国有色金属学会会刊：英文版 2001年第2期11卷 188-191页

作者：李纬民刘助柏赵长才刘国晖 LI Wei-min School of Mechanical Engineering Yanshan University

The fundamental principle and method of the determining of structure parameters for the hydraulic elastic bulging roller were discussed. The relationship among crown of roller, hydraulic pressure and thickness of roller sleeve was studied. Aluminum was chosen as experimental material to accomplish the dynamic load experiment. The hydraulic elastic bulging roller exerts good effect on shape control and therefore has a broad application prospect in engineering. [

关键词： hydraulic bulging roller shape control structure parameters

Frictional characteristics of sheet metals with superimposed ultrasonic vibrations

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Journal of Central South University 2018年第8期25卷 1879-1887页

作者： CAO Miao-yan LI Jian-chao LIU Yan-yang YUAN Ya-ning zhao chang-cai DONG Guo-jiang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004China Chinese Academy of Agricultural Mechanization Sciences Beijing 100083China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education of China Yanshan UniversityQinhuangdao 066004China College of Vehicles and Energy Yanshan UniversityQinhuangdao 066004China

The forming performance of sheet metals in the deep-drawing process with ultrasonic vibrations can be improved by the surface effect between the sheet metal and the die.A sheet metal friction test with ultrasonic vibrations is performed to explore the cause of the surface *** frictional characteristics are investigated,and the corresponding friction expressions are established based on the contact mechanics and the elastic–plastic contact model for rough *** is caused by the elastic–plastic deformation of contacting asperities under normal *** actual contacting region between two surfaces increases with normal loads,whereas the normal distance *** normal distance between the contacting surfaces is changed,asperities generate a tangential deformation with ultrasonic vibrations,and the friction coefficient is eventually *** vibrations are applied on a 40Cr steel punch at the frequency of 20 kHz and the amplitude of 4.2μ*** the friction tests,the punch is perpendicular to the surface of the magnesium alloy AZ31B sheet metals and is sliding with a relative velocity of 1 mm/*** test results show that the friction coefficient is decreased by approximately 40%and the theoretical values are in accordance with the test values;Ultrasonic vibrations can clearly reduce wear and improve the surface quality of parts.

关键词： friction ultrasonic vibrations sheet metals contact model

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金属薄壁管件外压缩径成形理论及实验研究

中国有色金属学报 2018年第3期28卷 586-593页

作者：杜冰谢军关风龙张鑫赵长财燕山大学先进锻压成形技术与科学教育部重点实验室秦皇岛066004

起皱失稳问题是空心薄壁类零件在加工和应用领域的主要瓶颈。基于此,对金属薄壁管件缩径成形过程中的弹塑性失稳规律进行研究,提出预测缩径褶皱、提高成形件质量的方法及技术手段。基于***线性屈曲理论,推导了管坯均布外压作用下的环向... 详细信息

起皱失稳问题是空心薄壁类零件在加工和应用领域的主要瓶颈。基于此,对金属薄壁管件缩径成形过程中的弹塑性失稳规律进行研究,提出预测缩径褶皱、提高成形件质量的方法及技术手段。基于***线性屈曲理论,推导了管坯均布外压作用下的环向弹性及塑性起皱临界载荷表达式;探讨了成形条件及材料参数对管材抗起皱性能强弱的影响。利用固体颗粒介质缩径工艺实现了AA7075管材不同热处理条件下的缩径成形,工艺试验验证了管材缩径成形起皱失稳理论的相关结论。

关键词： AA7075铝合金管件缩径成形起皱失稳固体颗粒介质成形