深孔筒套精密成形工艺及模具设计

目的对深孔筒套精密件成形过程与难度进行分析,确定其工艺方案,设计出合适的成形模具,并保证零件尺寸精度。方法通过结合UG与CAD软件,制定零件成形工艺方案,绘制零件成形模具图。结果该零件须通过三套成形模具进行冷挤压成形,包括一次复合挤压和两次正挤压。结论该零件的成形模具能保证深孔筒套零件的成形精度并使其较好成形。     

基于 Deform-3D 的车用下轴套零件冷挤压模具结构优化设计

目的分析挤压成形中车用下轴套零件成形表面出现的折叠缺陷,优化挤压上凹模的底部出口斜度、下凹模的入口斜度和挤压深度等主要成形工艺参数。方法采用DEFORM-3D软件,对汽车下轴套零件的冷挤压成形工艺进行了系统的有限元数值模拟试验。结果挤压成形模具结构设计不合理,导致在成形过程中模具分型面处金属出现汇流并形成折叠。结论通过优化挤压模具结构,使金属成形良好,无折叠缺陷出现,最终获得了较为合理的冷挤压模具结构。     

双凸模冷径向挤压十字轴的模拟

针对十字轴零件特征,设计了十字轴零件的一次性冷挤压成形工艺,基于有限元分析软件Deform-3D平台,对十字轴冷挤压成形过程进行模拟。通过有限元数值模拟,对十字轴挤压过程中金属径向流动、加载载荷变化、内部的等效应力分布等做了分析,为汽车十字轴零件的单道次挤压成形生产提供数值参考。     

深孔变壁厚锥形件冷挤压工艺与模具设计

深孔变壁厚锥形件需要3次挤压成形,给出了该零件冷挤压工艺和实用的模具结构,论述了反挤压工序件与成品正挤压模腔的关系,以及凸模和凹模设计.该模具采用伸缩式双级卸料装置,实现较大行程的卸料.     

205轴承内外圈套料的温-冷联合成形工艺的研究

叙述了采用复合挤压成形的高厚比大的环形零件成形方法,从环形零件内外圈的结构分析、坯料尺寸的确定、变形程度的计算,以及模具设计和选择挤压设备等方面作了较为详细的研究,为其他具有类似几何形状的零件成形工艺采用温-冷联合成形提供了基本设计流程.     

细密沟槽铝合金挤压件模具的改进

对细密沟槽铝合金挤压件的结构进行了分析,研究和探讨了该类冷挤压件的成形过程.通过对挤压过程中金属的流动,以及模具的受力分析和模具结构的改进,解决了该类零件在挤压过程中上模的断齿问题.     

方形孔轴套冷挤压成形工艺研究及数值模拟分析

目的通过对方形孔轴套的分析,确定冷挤压工艺成形方形孔轴套的可行性,为方形孔轴套的实际生产提供理论依据和支持。方法结合Deform软件,对方形孔轴套的挤压成形过程进行了数值模拟,重点分析了零件在冷挤压成形过程中的应力场、应变场的变化情况。结果通过模拟得出,在成形难度大的区域没有出现折叠和破裂缺陷。结论确定了冷挤压工艺成形方形孔轴套的可行性。     

固定碗冷挤压工艺及模具设计

通过对固定碗零件冷挤压工艺进行了分析,介绍了固定碗零件冷挤压工艺及设备选择,分析了高分子润滑剂和磷化皂化的特点,提出了采用高分子润滑剂进行毛坯润滑,介绍了镦扁的目的,挤压模具结构设计,实现了该零件冷挤压加工的顺利进行。     

T2紫铜微正挤压件表面形貌与微观组织分析

为便于取出微正挤压零件,设计了具有分瓣式结构的微正挤压凹模,并成功成形出最小挤出杆直径为0.25 mm的微正挤压件.采用扫描电子显微镜(SEM)及金相显微镜对微正挤压件的表面形貌及微观组织进行了观察。结果表明,随着挤出杆尺寸的减小或晶粒尺寸的增大,内外层材料的非均匀塑性变形程度增加;当挤出杆尺寸降低到亚毫米尺度时,微挤压成形件发生了一定弯曲;微正挤压件纵向和横向微观组织的非均匀分布表明,在微正挤压成形过程中材料在纵向和横向上都经历了严重的非均匀塑性变形.材料的非均匀塑性变形程度是随着挤出杆尺寸的减小或晶粒尺寸的增加而不断增加的.     

拖钩套筒复合冷挤压数值模拟与毛坯优化

将挤压模具视为刚体,采用有限元分析软件MARC,对拖钩套筒零件进行了冷挤压过程的数值模拟计算。根据各主要阶段等效应力及等效应变的分布,总结了挤压过程中金属材料塑性流动的规律。以最大挤压力为目标,对毛坯的尺寸进行了优化,为挤压工艺的改善提供了依据。根据计算结果,得出了挤压完成后零件所受最大主应力数值及其分布规律,为后期模具强度的研究奠定了基础。     

挤压法制备各向异性稀土永磁环的研究

由于塑性加工可以形成材料的各向异性组织，采用塑性加工方法制备稀土永磁材料，成为继烧结法和粘结法之后．人们所注目的研究课题。本文以快淬Nd-Fe-B粉末为原料，经过冷压和热压制坯，采用反挤压方法制备了外径为∮10mm、壁厚为2mm的Nd-Fe-B稀土永磁环。研究结果表明，挤压态磁环具有各向异性组织。     

汽车空调压缩机驱动盘冷挤压的 Deform 模拟

采用冷挤压工艺成形汽车空调压缩机驱动盘。用Deform-3D软件对冷挤压过程进行数值模拟,分析了冷挤压成形过程金属流动、等效应变和速度分布等规律。结果表明,用冷挤压工艺成形驱动盘,成形载荷小,充填效果好,材料利用率较高。     

Verbesserung des Eigenspannungszustands beim Kaltfließpressen durch den aktiven Einsatz eines gesteuerten Gegenstempels

By using an active counter punch during cold extrusion, the residual stress of the component can significantly be improved, which can increase its fatigue strength. In general, the workpieces produced through full‐forward extrusion are characterized by a strongly unfavourable stress state: The resulting high axial tensile residual stresses on the surface as well as the steep stress gradient accelerate the formation and the growth of cracks during cyclic loading. A system developed by the authors, consisting of a counter punch actively employed during the forming process allows improving the residual stress state of the final product. This result is obtained through a homogenization of the deformations in the samples during the cold extrusion. Therefore, a finite element simulation of the process was developed in Simufact Forming®. The simulation was experimentally validated by using the two austenitic steels 1.4307 and 1.4404. Another focus is the development of suitable measuring strategies for the X‐ray residual stress analysis with the sin²Ψ‐method to ensure the quality of the measurement results despite coarse‐grained and anisotropic microstructures. The results of the simulations and the experiments show that his technique has a considerable potential to increase the product quality without modifying the process time.     

花键冷挤压用组合凹模内径收缩量的计算

为研究花键组合凹模压入预应力圈时内径的变化规律,实验研究了轴向压合量对凹模内径变化的影响规律.在理论分析的基础上,推导了组合凹模压合后凹模内径的计算公式,并通过实验进行了验证.研究表明:花键挤压用组合凹模压合时,大径比等直径的圆凹模内径收缩得慢,而小径则比等直径的圆凹模内径收缩得快.     

多向加载近净成形研究动态

题.     

星形套冷态闭塞式精锻成形分析

目的提出星形套冷精锻成形工艺优化方案,提高模具使用寿命,对生产操作进行规范。方法分析零件结构,确定了合理的分模面;运用数值模拟方法,选取不同的冲头进给速度和冲头形状,对星形套冷精锻成形过程进行了模拟分析。结果获得了冷精锻成形过程中冲头进给速度和冲头形状对温度场、应力场、金属速度场、工作载荷和模具寿命的影响。结论通过分析冲头进给速度和冲头形状对星形套成形的影响,并对其进行控制和优化,得出了最优工艺参数区间,为实际生产提供了参考依据和理论指导。     

Optimization of the diaphragm forming process with regard to product quality and cost

The diaphragm forming process used for the cost efficient production of thermoplastic composite components has been experimentally investigated. The process has been optimized with regard to product quality and cost. For the process optimization a new generic concept is introduced. The proposed concept involves quality and cost sensitivity analyses by considering the process parameters as variables. For deriving relations between process parameter variation and component quality features, as well as between process parameter variation and component costs, an extensive experimental parametric study was made. For the investigation, the thermoplastic composite APC-2/AS4 was used. The manufactured parts were different, aircraft structure like, simple shapes. Cost estimation relationships were established by using the activity based cost concept. Using the derived empirical relations for the quality and cost sensitivity analyses, the developed process optimization concept could be implemented. The investigation presented the need for the evolution of the diaphragm forming technique into a new ‘cold’ diaphragm forming technique. To evaluate the ‘new’ technique, a testing facility on experimental (laboratory) scale was devised. Simple shape parts from the thermoplastic Borealis PP/E-glass were manufactured with satisfactory quality. The cost for producing components using the cold diaphragm forming technique was estimated and it was found to be significantly lower compared to the cost for producing the same components using the autoclave or conventional diaphragm forming techniques.     

Effect of fabrication parameters on carbon fibre reinforced magnesium matrix composite components

Carbon fibre reinforced magnesium matrix (C_f/Mg) composite components were made by liquid–solid extrusion process following vacuum infiltration technique. The effect of varying fabrication parameters (extrusion temperature, infiltration pressure and filling pressure) on the forming quality of C_f/Mg components was investigated. The experimental results showed that the extrusion temperature and the infiltration pressure played important roles, and the filling pressure played a secondary role. The components can be obtained at an extrusion temperature of 590°C, an infiltration pressure of 20?MPa and a filling pressure of 0.2?MPa. The ultimate tensile strength of the C_f/Mg composite components was 290?MPa, which was increased by 81% compared with that of casting AZ91D.     

底排船尾精化毛坯工艺改进实践

以某产品底排船尾毛坯为对象,进行了冷挤压成形工艺改进研究,通过模具设计制造控制,合理的选用软化处理参数及冷挤压时的润滑剂,实现该零件冷挤压加工的顺利成形,进而达到了精化毛坯的目的,提高了材料利用率。