Vibration of Pressure Loaded Nonlinear Rectangular Plates with Cross Stiffener

The resonant frequency response of large static pressure loaded, nonlinear rectangular plates with a cross stiffener have been investigated theoretically. The nonlinear Berger equation was solved by applying the finite-difference method. Replacing the partial differential equation governing the small amplitude vibration of static pressure loaded plates and the boundary conditions by the finite-difference equations approximately, the simultaneous, homogeneous, and algebraic equations are obtained. Under the condition that the determinant of coefficient matrix must be equal to zero, the resonant frequencies are determined. The numerical procedure is simpler than the procedures based on the von Kármán theory, and reasonable results are obtained.     

Prediction of Stress and Strain Based Forming Limit Diagram During Tube Hydroforming Process

Hydroforming process is most widely used in automotive industries. The current work involves the formability evaluation of DQ Steel and Al 5182 tubular blanks using the bulge test simulation done on PAM-STAMP 2G solver. The dependence of stress based forming limit diagrams are also evaluated in complex loading paths in case of hydro-forming as they are independent of strain paths.     

低品位软锰矿加压浸出过程中铝的行为分析

通过对软锰矿加压浸出过程中铝的行为研究,可知温度、压力、时间对锰、铝的浸出率都有较大影响。实验结果表明:在保证锰的最大浸出率条件下,抑制铝被浸出的最佳单因素实验条件为:压力0.9MPa、温度120℃、时间80～120min,此实验条件下铝的浸出率可降低至8%左右,减轻了后续的净化除杂工序负担。     

铝挤型汽车零部件功能开发与过程控制

铝合金型材具有强度高、重量轻、易成型、易加工和良好的机械性能、焊接性等特性被广泛运用。汽车零部件产品的设计与开发大量的使用了铝件代替铁件。对于铝挤型汽车产品的零部件功能开发必须进行充分的设计验证和有效的合格检验,确保汽车产品的安全性和可靠性。本文主要阐述铝挤型汽车部件各种功能的开发过程与控制。最终满足产品的设计和使用要求。     

铝电解氧化铝输送除杂系统改造

本文根据中国铝业青海分公司第一电解厂净化系统氧化铝输送系统中影响输送系统堵塞、不畅的杂质的来源进行了分析,并针对净化系统氧化铝输送系统的现状,提出了具体的改造方案,解决了影响电解正常生产的氧化铝输送系统系统不畅的问题。对生产具有很大的现实意义。     

大直径薄壁铝合金导管的充液弯曲成型工艺研究

设计了大直径薄壁铝合金导管充液弯曲的成型工艺方法,通过三步弯曲成型,实现了大直径薄壁铝合金导管的充液弯曲。对导管弯曲后的弯曲形貌、椭圆度、减薄率进行了分析,三项指标均符合设计要求。并对导管的金相显微组织进行了观察,发现导管弯曲后的金相组织和母材无明显变化,同时对导管进行了液压强度试验,试验结果满足工作压力的要求,从而验证了该工艺方法的可行性。     

Material Flow Control in High Pressure Sheet Metal Forming of Large Area Parts with Complex Geometry Details

Working media based forming processes show advantages compared to the conventional deep drawing in the range of sheet metal parts with complex geometry details. By High Pressure Sheet Metal Forming (HBU), complex parts can be formed with reduced tool costs, fewer process steps, and improved part properties, particularly by the use of high strength steels. In order to use these advantages to full capacity, the material flow into the area of the geometry details needs to be optimised. The key element for the material flow control is a multi‐point blank holder. In combination with flange draw‐in sensors, a closed loop flange draw‐in control can be built up which guarantees a reproducible material flow and, consequently, defined part properties. Furthermore, a favourable pre‐distribution of sheet metal material can be reached which leads to a widening of the process limits. Considering a large area sheet metal part with a complex door handle element as example, strategies for the material flow control will be discussed in this paper. The conclusions are based on FE‐simulations as well as experimental findings.     

楔横轧单双楔端面移动量变化规律的实验研究

为了弄清楔横轧多楔端面移动量的变化规律,合理设计多楔模具,实现多楔长轴类汽车等零件的经济化生产,对单楔与双楔楔横轧端面移动量规律进行测试,得到端面移动量随工艺参数的变化规律,单楔与双楔端面移动量的对应关系,研究结果为设计多楔模具提供理论基础。     

6061铝合金带筋圆管在线淬火模拟分析

通过喷水淬火实验获得6061铝合金的冷却曲线,结合数值计算方法获得材料的在线淬火换热系数,运用ABAQUS有限元软件对带筋圆管在线淬火过程进行了动态模拟。结果表明：在淬火开时阶段,换热系数较小,随着淬火温度降低,换热系数逐渐增大至峰值2kW／m。℃,随后又逐渐减小;在圆管筋部外边缘处冷却最快,型材内表面与筋的连接处冷却最慢;淬火开始2s内型材的整体温差近100℃,随后温差显著减小,型材各部分的温度趋于均匀;淬火初始阶段,管外壁及筋外壁表现为拉应力,管内壁和筋内壁表现为压应力,随着淬火的进行,压应力和拉应力互相转变,最大拉应力和压应力分别为21．7MPa和28．7MPa。     

6063-T6铝合金薄壁管材最佳时效工艺研究

试验研究了淬火后的预变形量和时效工艺对6063薄壁管材力学性能的影响,确定该合金薄壁管材的最佳时效制度为200±5℃,保温8h.工业化生产出了符合要求的6063薄壁管材.     

低碳铝镇静钢头坯洁净度研究

 低碳铝镇静钢（LCAK）常用于生产冷轧板,要求铸坯有高的洁净度。但连铸开浇阶段由于浇铸状态的不稳定,会严重恶化头坯洁净度。从铸坯成分和非金属夹杂物等方面系统研究了一定浇铸条件下低碳铝镇静钢头坯洁净度的变化,并讨论了头坯洁净度的影响因素。结果表明,头坯洁净度在开浇准数达到0.17后趋于稳定,这可为实际生产中铸坯质量评级提供帮助。研究发现恶化头坯洁净度的主要因素是中间包二次氧化,并且除了由空气造成的中间包二次氧化外,更大程度上的二次氧化是由中间包耐火材料及覆盖渣等因素造成的。还提出了几点改善头坯洁净度的措施,为生产实践提供一定的参考。     

汽车用铝合金零件的半固态触变压铸工艺研究

针对半固态触变压铸工艺特点，对国产J1128卧式冷室普通液态压铸机的压射系统和模具系统进行了结构改进．对压铸工艺参数进行了优化选择，并采用半固态专用铝合金AlSi6Mg2和商用铝合金A357开展了大量半固态触变压铸试验研究。结果显示，半固态触变压铸工艺与普通液态压铸有很大的不同，在压射室和模具预热温度分别为100℃和250℃、低压压力为4．0MPa、射料二速工作压力为12MPa、增压压力为20MPa、快压射速度为1．4m／s的条件下，可获得充型完好的汽车用铝合金半固态压铸零件。     

Prediction of Maximum Section Flattening of Thin-walled Circular Steel Tube in Continuous Rotary Straightening Process

Cross-sectional ovalization of thin-walled circular steel tube because of large plastic bending,also known as the Brazier effect,usually occurs during the initial stage of tube′s continuous rotary straightening process.The amount of ovalization,defined as maximal cross section flattening,is an important technical parameter in tube′s straightening process to control tube′s bending deformation and prevent buckling.However,for the lack of special analytical model,the maximal section flattening was determined in accordance with the specified charts developed by experienced operators on the basis of experimental data;thus,it was inevitable that the localized buckling might occur during some actual straightening operations.New normal strain component formulas were derived based on the thin shell theory.Then,strain energy of thin-walled tube(per unit length)was obtained using the elastic-plastic theory.A rational model for predicting the maximal section flattening of the thin-walled circular steel tube under its straightening process was presented by the principle of minimum potential energy.The new model was validated by experiments and numerical simulations.The results show that the new model agrees well with the experiments and the numerical simulations with error of less than 10%.This new model was expected to find its potential application in thin-walled steel tube straightening machine design.     

降低高压阳极铝箔升压时间的预处理工艺

为了提高铝电解电容器用高压阳极箔氧化膜的质量,降低阳极箔的升压时间,在高压箔化成前对腐蚀箔进行硝酸处理,提高了氧化膜的致密眭,减少其缺陷,大大降低了升压时间。     

Investigation on the Hydroforming Characteristics of Double‐layered Tubes

Double‐layered tubes consist of an inner tube and an outer tube. Both are similar in material, contact closely and deform simultaneously when subjected to external force. Hydroforming assembly technology has several advantages in the manufacturing of double‐layered tubes. In this study, the hydroforming characteristics of double‐layered tube are investigated. Free bulging tests are performed to produce formability diagrams of double‐layered tubes at various forming pressures and feeding amounts. In addition, the hexagonal‐shape hydroforming test is performed to estimate the dimensional accuracy of double‐layered tubes through the corner filling ratio and the gap between the inner and outer tubes. Besides experimental analyses, an analytical model that can predict internal pressure for the hydroforming of double‐layered tubes is proposed and experimentally validated in this study.     

应用视塑性方法研究Y型冷轧金属横截面的变形

应用视塑性方法研究了Ｙ型冷轧过程圆─平三角孔型系统金属横截面的塑性变形。在实验中采用激光刻制网格和真空电子束焊接技术，并且应用微机图像分析系统处理实验数据。实验给出了横截面的应变和等效应变的分布，结果准确、可靠。研究工作对Ｙ型冷轧工艺及孔型的设计具有一定的指导意义。     

Leaching Process Investigation of Secondary Aluminum Dross: The Effect of CO2 on Leaching Process of Salt Cake from Aluminum Remelting Process

For the recycling/disposal of aluminum dross/salt cake from aluminum remelting, aqueous leaching offers an interesting economic process route. One major obstacle is the reaction between the AlN present in the dross and the aqueous phase, which can lead to the emission of NH₃ gas, posing a serious environmental problem. In the current work, a leaching process using CO₂-saturated water is attempted with a view to absorb the ammonia formed in situ. The current results show that at a solid-to-liquid ratio of 1:20 and 3 hours at 291 K (18 °C), the extraction of Na and K from the dross could be kept as high as 95.6 pct and 95.9 pct respectively. At the same time, with continuous CO₂ bubbling, the mass of escaping NH₃ gas decreased from 0.25 mg in pure water down to <0.006 mg, indicating effective absorption of ammonia by carbonized water. Furthermore, the results in the case of the leaching experiments with synthetic AlN show that the introduction of CO₂ causes hindrance to the hydrolysis of AlN. The plausible mechanisms for the observed phenomena are discussed. The concept of the leaching of the salt cake by carbonated water and the consequent retention of AlN in the leach residue opens up a promising route toward an environment-friendly recycling process for the salt cake viz. recovery of the salts, utilization of CO₂, and further processing of the dross residue, toward the synthesis of AlON from the leach residues.     

汽车散热器用铝合金口琴管的生产工艺与模具设计

汽车空调器用多孔铝扁管（口琴管）断面形状复杂、精度要求高，生产难度较大。我公司在试验研究的基础上，改进了生产工艺及模具设计，所生产的口琴管完全可以满足汽车空调器厂家的使用要求。