基于Abaqus的铝合金汽车覆盖件快速超塑成形分析

以汽车引擎罩外板为例,运用Abaqus有限元分析软件建立铝合金汽车覆盖件快速超塑成形的有限元模型。通过对引擎罩外板进行快速超塑成形仿真分析,确定了成形工艺条件,为实际生产提供工艺指导,以减少模具设计和实际生产工艺的盲目性。     

汽车覆盖件的拉伸成形

汽车覆盖件的拉伸成形贵州安顺市云马飞机制造厂张庆海为确保汽车覆盖件的拉伸成形，在拉伸过程中，必须对材料进行充分拉伸，使材料处于极限范围内进行拉伸，使材料均衡地流入凹模，以保证拉伸件的质量。下面以两例进行分析，研究保证拉伸成形质量的工艺措施。１后侧围外...     

铝合金覆盖件快速超塑成形技术的研究

快速超塑成形技术是将热冲压与超塑气胀相结合的一种技术,它利用热冲压的快速性和超塑性的良好成形性来解决铝合金冲压难成形和超塑成形慢的难题.在5083铝合金性能研究的基础上,采用该工艺对某车型引擎罩的成形进行了实验.结果表明,该工艺切实可行,并且生产效率较高.     

提高汽车覆盖件成形质量的途径

<正> 在汽车生产中,有大量的覆盖件在成形过程中会产生各种各样的缺陷。除了存在表面划伤等缺陷外,危害性最大的莫过于破裂和起皱。产生这两种缺陷的原因很多,其中有:零件的结构设计是否具有良好的结构工艺性,工序安排、工艺补偿、毛料外形、零件选材是否合适,毛料板面及周边状态是否良好,有否锈蚀;模具间隙是否均匀,模具     

汽车覆盖件的对向液压成形

1.前言采用对向液压对薄板金属拉深成形的方法,以往多数被用于加工形状较小,需要多工序的难成形零件。最近在试制汽车外覆盖件等大型零件时常被采用。现对采用这种成形方法进行各种覆盖件成形试验,与过去惯用模具成形方法比较所具有的特点,作一介绍。     

络筒机用铝合金槽筒的超塑成形研究

针对络筒机用铝合金槽筒的结构和技术特点,采用超塑成形的加工方法,研究络筒机用铝合金槽筒超塑成形工艺和参数选择原则,并对成形模具的设计和使用要点进行阐述。结果表明,采用超塑成形工艺可以节约材料20%以上,节约能源30%,节约设备投资50%以上,并且可以减少工序,缩短生产周期。     

铝合金覆盖件快速超塑性成形技术

快速超塑性成形技术是将热冲压和超塑气胀成形集成复合的新型工艺,通过对该工艺过程研究以及对复合工模具的优化设计,采用商用供货态工业铝合金5083板材成形出了某型号乘用车的引擎盖。结果表明,这种集成复合的快速超塑性成形技术工艺先进,切实可行。     

汽车覆盖件成形度分析方法探讨

根据成形度的定义 ,利用UG软件的图形处理工具 ,对汽车覆盖件拉伸的成形度进行分析 ,并给出发动机罩的分析实例     

汽车大型铝合金覆盖件的充液成形技术

铝合金覆盖件的应用是汽车轻量化的关键,但其制造难度较大。通过研究铝合金发动机罩外板的充液成形工艺过程,了解先进柔性技术在汽车领域应用的可行性。分析了工艺参数中液室压力与凸模行程匹配及压边力对板料减薄率的影响,从成形极限上判断零件无起皱、破裂现象的范围。获得最优的整形液室压力为12～20 MPa,压边力过小,板料不能充分塑性变形,压边力过大,板料易失稳破裂,最优的恒定压边力范围为1600～2000 k N。研究表明,采用板材充液成形柔性制造工艺,可降低噪音,无冲击线,且由于液室压力的作用,滑移线减小,可提高大型铝合金弱刚度板材的质量。     

Superplastic deformation behavior of 7075 aluminum alloy

A study has been made to investigate the effect of a prior amount of warm rolling on the superplastic forming behavior of a standard grade 7075 aluminum alloy. The thermomechanical treatment process presented for grain refinement includes furnace cooling from the solution treatment temperature to the overaging temperature, warm rolling from 65–85% deformation, recrystallization, and artificial aging treatment. Increasing the amount of warm rolling beyond 80% deformation does not produce material with higher elongation to failure when the thermomechanical treatment process presented is used. The largest value of elongation to failure was 700%, which was obtained for a specimen having a grain size of 8 μm at a strain rate of 6×10⁻³S⁻¹. The fracture surface exhibits a granular appearance indicative of an intergranular fracture mode. Dislocation activities within grains were observed, indicating the occurrence of dislocation slip during grain boundary sliding.     

AZ41镁合金超塑性成形特性

研究AZ41镁合金在热轧(无后续热变形)条件下的显微组织变化,以确定其在超塑性成形工艺中的适用性,并确定最佳成形参数.采用高温拉伸试验和热气体胀形试验对材料在不同应变速率(1×10?1～1×10?3 s?1)和温度(350～450℃)下的成形性进行评估.利用GOM Aramis相机进行圆形网格分析,了解峰值应变和材料减...     

铝合金车体制造关键技术研究

全铝结构铝合金车体正逐步在中国各城市的轨道车辆、铁路高速动车组上推广应用,制造高质量的铝合金车体是保证车辆运行的必要条件文章.论述了制造铝合金车体的关键技术和各种工艺方法的局限性,指出灵活运用工艺方法的规则.     

5A90铝锂合金电子束焊焊板超塑性变形力学行为

通过高温拉伸试验研究了5A90铝锂合金电子束焊焊板超塑性变形行为. 结果表明,5A90铝锂合金电子束焊焊板具有良好的超塑性变形能力,焊板的峰值流变应力随温度升高及初始应变速率的减小而减小,应变速率小于1×10-2/s时,焊板峰值流变应力小于32 MPa;焊板的断后伸长率随温度的升高和初始应变速率的增大而先增大再减小,在450℃,5×10-3/s断后伸长率达到最大为171.1%. 提出变形比例系数K（接头与母材断后伸长率的比值）,评价焊板中接头的超塑性变形协调能力,在各变形条件下K值均达到70%以上.     

工业牌号铝合金的超塑性能及微观组织演化特征

采用实验方法研究国外广泛用于汽车车身板件冷冲压成形的工业牌号铝合金板材AA5182和6016的超塑性能,以及超塑变形中微观组织的演化特征。通过超塑性单向拉伸试验、材料变形前后的微观组织观察和自由胀形试验,揭示出铝合金AA5182具有一定的超塑性能,而铝合金6016的超塑性能很低。铝合金AA5182在温度为375℃、应变速率为1.67×10-3/s时,材料的延伸率达到210%,m值达到0.25;在温度为500℃、应变速率为1.67×10-2/s时,材料延伸率达到225%,m值达到0.35。     

工业AA1200铝合金薄板拉伸成形模拟和实验研究(英文)

对工业AA1200铝合金薄板拉伸成形的模拟和实验结果进行比较和评估。采用单向拉伸试验得到模拟所需输入参数。根据von Mises和Hill-1948屈服准则,采用Abaqus/Explicit有限元软件分析成形过程。将冲压力和应变分布的模拟结果与实验结果进行比较和验证。结果表明:在这两种情况下,使用各向异性屈服准则模拟的结果与实验结果更吻合。     

Superplastic forming characteristics of fine-grained 5083 aluminum

Superplastic forming characteristics of a fine-grained 5083 aluminum sheet have been investigated by means of gas-pressure forming of a rectangular pan. This part geometry lends itself to a simple representation in terms of nearly one-dimensional sheet stretching and permits reasonably rigorous control of strain rate throughout the forming cycle. This study followed a study of the uniaxial tensile properties carried out on this alloy. A two-stage forming cycle, which comprised a short, rapid prestraining stage followed by a stage of slower rate of superplastic straining, was used because the uniaxial tensile work showed enhancement of superplastic response of this alloy under this condition. The study examined the effect of process parameters such as initial gas pressurization rate, level of hydrostatic pressure, and lubricants on the thinning characteristics of the sheet, especially along the die entry radii. The gas pressure/time cycle was suitably modified to avoid premature sheet failure due to excessive sheet thinning or cavitation. Cavitation under the biaxial forming condition and the effect of hydrostatic pressure on cavitation suppression were evaluated. A defect-free pan with sharp corners was formed.     

Superplastic forming gas pressure of titanium alloy bellows

The complex superplastic forming (SPF) technology applying gas pressure and compressive axial load is an advanced forming method for titanium alloy bellows, whose forming process consists of the three main forming phases namely bulging, clamping and calibrating phase. The influence of forming gas pressure in various phases on the forming process was analyzed and the models of forming gas pressure for bellows were derived according to the thin shell theory and the plasticity deformation theory. Using the model values, taking a two-convolution DN250 Ti-6Al-4V titanium alloy bellows as an example, a series of superplastic forming tests were performed to evaluate the influence of the variation of forming gas pressure on the forming process. According to the experimental results these models were corrected to make the forming gas pressures prediction more accurate.     

轨道车辆铝合金车体焊接现状及搅拌摩擦焊新技术应用

分析了轨道车辆铝合金车体焊接的应用现状及存在的技术问题,着重阐述搅拌摩擦焊技术在铝合金中厚板部件中的研究应用进展,并提出了搅拌摩擦焊技术在轨道车辆铝合金车体制造行业未来的发展趋势。     

Formability and cavitation behavior of superplastic AA5083 aluminum alloy under biaxial tension

The superplastic forming potential of two fine-grained 5083 aluminum alloys were studied under biaxial tension using a pneumatic bulge test. Experiments were performed at temperatures ranging from 475 to 525 ℃ with three different strain paths ranging from equi-biaxial to approaching plane strain. The shape of the forming limited diagram（FLD） is found to be significantly different from FLDs commonly used in room temperature stamping. The effects of temperature on final thickness distribution, dome height and cavitation were investigated for the case of equi-biaxial stretching. Increasing temperature in free bulge forming can improve the thickness distribution of final parts but have no significant effect on dome height. The results indicate that determination of forming limits in SPF cannot be represented with a simple FLD and additional metrics such as external thinning and internal cavitation needed to determine the SPF potential of a material.