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在汽车零部件的生产过程中,冲压模具拉延模面设计的优劣决定了冲压件的成形性、成形质量和型面尺寸精度。以我公司生产的某车型后地板左/右纵梁零件为例,零件形状复杂、拉延深度深,对拉延模具型面设计要求较高,生产中零件变截面拐角区域易出现拉延开裂现象,严重影响零件的工艺质量及生产效率。基于CAE分析,对其初始设计加工的拉延模面拉延成形过程进行数值模拟,依据CAE分析结果对零件拉延模面设计进行修改优化,得出合理的拉延模面用于模具加工制造,并通过FLD实验验证分析结果,为后续复杂零件的拉延模面设计提供参考,缩短了设计周期。 相似文献
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详细分析了某汽车外板拉延件的成形工艺,利用Dynaform分析软件对拉延件的成形过程进行数值模拟,获得了坯料流入量分布、拉延结果、板料厚度变化及FLD图等模拟结果.通过对模拟的结果分析,提出了减少成形缺陷的措施.根据分析结果进行拉延模具设计,确定了拉延模具结构及压力中心,设计了上模、压边圈及下模,详细阐述了其工作原理,并进行了实际冲压试验.结果显示,借助数值模拟技术实现了拉延模的结构优化、提高了模具设计效率与可靠性,并最终通过实际实验调试获得满足质量要求的汽车外板零件. 相似文献
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介绍了一种具有复杂形状特征的两座电动汽车顶盖零件及其冲压成形方法。针对该汽车小批量多品种的特点,提出了顶盖冲压模具多种车型配置共用模具的目标,经过分析对比,选择拉延模独用、后续OP20~OP40整形模共用的技术方案。对该顶盖材料进行测试并建立了材料参数模型,采用数值模拟的方法,分析顶盖成形性问题。针对成形过程中的凹面和起皱问题,通过增加强压及调整吸皱筋高度,抑制凹面和尾部整形起皱缺陷的产生。结果表明:对于该种零件,3 mm高度腰型的吸皱筋的效果最好,经过几次精确的CAE模拟分析及相应调整后,材料成形充分,减薄率和应力、应变均满足要求。 相似文献
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覆盖件拉延模型工艺补充部分的参数化设计 总被引:3,自引:1,他引:3
拉延工艺设计是汽车覆盖件冲压工艺设计的重要内容,也是在对该类零件进行成形过程数值模拟时的前序工作,因此一个完整的汽车覆盖件冲压成形数值模拟软件应该包括覆盖件拉延模型设计模块,以便于将通过CAD软件输入的产品模型向适用于CAE分析的拉延模型转化.拉延工艺设计主要包括冲压方向调整、压料面和工艺补充部分的设计以及拉延筋布置等工作.本文分析了拉延件常用工艺补充部分的形状特点,在此基础上介绍了在自主开发的CAE软件系统Sheetform中,以参数化方式进行工艺补充部分的设计,并利用凹模开口线和零件边界线的位置对应关系自动求解工艺补充特征截面线和构造工艺补充组成曲面的算法,研究了曲面生成中所遇到的问题和相应的解决方案.整个设计过程操作简单,自动化程度高,简化了CAE分析中的模具型面设计工作. 相似文献
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曲面形件拉延变形过程数值模拟 总被引:1,自引:0,他引:1
运用有限元模拟软件MSC.Marc对不锈钢带凸缘半球面形件和抛物面形件进行了数值模拟研究.首先采用拉延成形方式对半球面形件和曲面形件进行数值模拟,模拟了它们在不同工艺参数下的成形过程.从模拟结果中分析应力、应变和材料厚度的分布与变化,分析了凹模圆角半径、凸模形状对拉延成形过程的影响,得出在拉延成形方式下,凹模圆角半径R=10 mm时成形性与成形质量最佳;为了比较不同成形工艺对曲面形件成形的影响,对半球面形件进行了胀形成形模拟,采用相同的分析方法得出,胀形时的变形程度较大,胀形后的材料厚度较薄,坯料没有增厚现象. 相似文献
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《热加工工艺》2015,(13)
基于正交试验法应用有限元数值模拟对双相不锈钢大型封头成形的工艺参数进行了系统性的多目标优化研究,利用直观分析法和排队评分法获取了凸凹模间隙、凹模入口圆角半径、拉延筋高度、拉延筋形状、拉延筋位置对成形质量、减薄率、回弹量的影响主次,得到了最优工艺参数组合,并对优化结果进行了生产验证。结果表明:采用凸凹模间隙11 mm,凹模入口圆角半径40 mm,位置在中间高度为20 mm的矩形拉延筋得到的封头无起皱、鼓包等成形缺陷,且封头最小壁厚为9.33 mm,最大壁厚为11.19 mm,回弹量较小。生产实际与模拟结果基本一致。采用该组工艺参数能提高双相不锈钢封头的成形质量。 相似文献
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Deng-Kui Zhang Guo-Qing Wang Ai-Ping Wu Ji-Guo Shan Yue Zhao Tian-Yi Zhao Dan-Yang Meng Jian-Ling Song Zhong-Ping Zhang 《金属学报(英文版)》2019,32(6):684-694
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone. 相似文献
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After nearly two years'tense construction the first phase of industrialized base of Shenyang Research Institute of Foundry 《中国铸造》2008,5(1):63-64
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation. 相似文献
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Z. Sun S.L. Zheng Y. Zhang 《金属学报(英文版)》2007,20(3):187-192
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process. 相似文献
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R. González-Martínez 《金属学报(英文版)》2007,20(4):235-240
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke. 相似文献
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The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C). 相似文献
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The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel. 相似文献
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This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before. 相似文献
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Chao Yang He-Fei Huang Massey de los Reyes Long Yan Xing-Tai Zhou Tian Xia De-Liang Zhang 《金属学报(英文版)》2015,28(7):809
Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties. 相似文献
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Lei Li Bo Xu Wei-Ping Tong Hui Zhang Chun-Yan Ban Li-Zi He Zhi-Hao Zhao Yu-Bo Zuo Qing-Feng Zhu Jian-Zhong Cui 《金属学报(英文版)》2015,28(6):725
A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed. 相似文献
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综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。 相似文献