共查询到18条相似文献,搜索用时 140 毫秒
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介绍了半锥角<1°的LF6合金锥筒旋压成形过程。实验表明,LF6合金小锥度铝筒零件,用筒形锻坯在直筒芯模上变薄旋压,再用小锥度芯模普旋收锥成形是可行的。文章分别对确定初始锻坯尺寸、室温下强旋变薄铝筒、加热普旋成锥形零件以及实验中出现的问题进行了说明。实验为LF6合金小角度无缝锥筒塑性加工成形提供了参考。 相似文献
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直齿圆柱齿轮温挤压成形的数值模拟 总被引:6,自引:2,他引:6
用优化后的凹模结构对直齿圆柱齿轮的温挤压成形进行了数值模拟 ,结果表明 ,以入模角为 180°、挤压筒内径等于直齿轮齿顶圆直径 ,且在齿根圆处不倒角为特点的凹模形式对齿形成形效果良好 ,此种凹模形式能够解决齿形角隅充不满的难题 ,非常适合直齿圆柱齿轮的挤压精密成形 相似文献
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《锻压技术》2021,46(5):94-100
针对锥筒形件剪切-拉深复合旋压时可旋性表征困难的问题,提出采用可旋性表征曲线对其进行表征。基于Abaqus软件建立了镍基高温合金锥筒形件全流程复合旋压成形有限元模型,分析了不同半锥角锥筒形件的破裂及起皱情况,进而获得其极限拉深系数;在此基础上,构建了锥筒形件剪切-拉深复合旋压成形的可旋性表征曲线,获得了锥筒形件复合旋压成形时的安全区以及破裂起皱区,并通过复合旋压工艺试验验证了有限元模型的可靠性。结果表明:采用剪切旋压时的半锥角为横坐标、拉深旋压时的极限旋压系数为纵坐标所构建的可旋性表征曲线,可实现对锥筒形件剪切-拉深复合旋压成形可旋性的有效表征。 相似文献
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传统强力旋压是固体火箭发动机筒体生产的工艺方法,由于只采用旋轮与芯模匹配的方式,工件外侧表面仅仅发生剧烈的塑性变形,而贴近芯模的内侧的筒体材料应变明显小于外侧,从而造成在强力旋压后的筒形件内、外表面塑性变形不均匀、性能不一致及柔性差等问题,另外,传统强力旋压内芯模柔性差,制造费用高,尤其不符合大直径小批量的固体火箭发动机筒体的工业化低成本制造的要求,因此需开展固体火箭发动机筒体对轮旋压工艺技术的研究。因此,本文基于有限元软件ABAQUS,建立材料为30CrMnSiA筒形件对轮旋压有限元模型,对其加工过程进行数值模拟,得出对轮旋压成形过程中内外表面应力对称分布,改善了工件内应力状态;通过单因素试验获取了减薄率、旋轮成形角、进给比对圆度误差、壁厚偏差的影响规律,综合优选出一组最优的成形工艺参数为成形角25°、进给比1.2、减薄率30%,从而为工业生产中对轮旋压技术的应用奠定了坚实的基础。 相似文献
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针对30CrMnSiA杯形件的电流辅助拉深旋压成形工艺,提出以旋压件的内径偏差和倒锥角作为成形质量指标;基于响应面法进行了30CrMnSiA杯形件电流辅助拉深旋压成形实验研究,分析了电流参数及旋压工艺参数对旋压件倒锥角的影响规律。结果表明:电流大小、预热时间与进给比对旋压件倒锥角具有显著的影响,旋轮与芯模相对间隙对倒锥角影响较小。电流大小与进给比对倒锥角的影响具有交互作用;预热时间与进给比对倒锥角的影响具有显著的交互作用。30CrMnSiA杯形件电流辅助拉深旋压最优工艺参数组合为:电流I=1200 A,预热时间th0=52 s,进给比f=0. 36 mm·r^-1,旋轮与芯模相对间隙δ=-38%。 相似文献
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Xu Hengqiu Li Mingzhe Zhang Rui Wang Dali Hou Fengyan Li Linlin Fan Guisen Shen Yujing Jilin University Changchun China Changchun Institute of Equipment Technology Changchun 《稀有金属材料与工程》2011,(Z3):78-81
In this paper, the process of thermal conventional spinning of Ti-6Al-4V alloy complex shape shell is studied by experiment. Billet for Ti-6Al-4V alloy board is headed in the spinning process for multi-pass conventional spinning forming. With two spinning mandrel, the first is conventional spinning pre-forming and the second is conventional end forming, vacuum heat treatment after each spinning forming. As results, the mandrel preheating temperature impacts the spinning and the appropriate temperature range plays an important role in the process of spinning. With supplemental heating means and infrared thermometer measurement ensure a stable temperature. Multi-passing thermal spinning Ti-6Al-4V alloy thins the billet thickness, using the feature obtaining the wanting complex shape shell of thick bottom and thin mouth. The spinning track, the number of spinning pass, feed rate affect the billet thinning. During thermal spinning process Ti-6Al-4V alloy rebound severe. The size reduction and feed have impact on the rebound. By modifying the spinning parameters and the mandrel repair to ensure the dimensional accuracy of workpiece. Spinning workpiece has fine grain and high strength. 相似文献
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对于镁合金带内筋筒形件的热强旋成形,旋前管坯的温度场分布对成形过程中的材料流动及旋压件的成形质量具有重要影响。基于多物理场耦合软件COMSOL,建立了ZK61镁合金带内筋筒形件热强旋旋前管坯电磁感应加热模型,模拟分析了不同感应加热参数条件下管坯温度场的分布情况,并通过实验验证了模型的可靠性。研究结果表明:相比电流强度,电流频率对管坯表心温差的影响更为显著,随着电流频率及电流强度的增加,管坯表心温差均逐渐增大;感应线圈的匝数及线圈与管坯的间距对管坯表心温差的影响较大,随着线圈匝数的增大,管坯表心温差近似呈指数形式增加,线圈与管坯的间距越大,管坯表心温差越小。 相似文献
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《Journal of Materials Processing Technology》2014,214(2):347-357
Cold tube drawing is a metal forming process which enables to produce tubes with high dimensional precision. It consists in reducing tube dimensions by pulling it through a die. Tube outer diameter is calibrated by a die and the tube inner diameter and thickness are calibrated by a mandrel. One of the major concern of metal forming industry is the constant improvement of productivity and product quality. In the aim of pushing the process to the limit the question is how far the material can be processed without occurrence of failure. In the present study, a long conical mandrel with a small cone angle was designed in order to carry out drawing tests up to fracture with experimental conditions very close to the industrial process. The FEM of the process was built in order to access the local stress and strain data. A specific emphasis was put on the friction characterisation. For that purpose force measurement during the conical mandrel experiments enabled to characterise a pressure dependent friction coefficient constitutive law by means of an inverse analysis. Finally, eleven failure criteria were selected to study the drawability of cobalt–chromium alloy tubes. The assessment of failure criteria based on damage variables or damage accumulation variables involved their calibration on uniaxial tensile tests. The experimental studies were completed by SEM fractography which enabled to understand the fracture locus and the propagation direction of the fracture. 相似文献
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采用考虑了各种热效应而建立的TA15钛合金加热剪切旋压多场耦合模型,研究揭示了TA15钛合金在各种热载荷和机械载荷条件下的变形机制.结果表明,高的工件加热温度和芯模预热温度可以减小工件厚向温度梯度,偏离率对变形区厚向温差的影响复杂,对贴模性影响显著且大的偏离率会恶化贴模性.工件和旋轮间的摩擦对温度差有显著影响.增加旋轮进给比会加大厚向温差但有助于贴模性的改善,这与冷旋的结果相反.大的旋轮安装角有助于减小厚向温差和改善贴模性. 相似文献
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旋压成形变壁厚双锥角锥形件的方法 总被引:3,自引:2,他引:1
应用同步旋压法强力旋压偏离正弦律一定范围的变壁厚双锥角锥形件,提出直接采用板料经二次强力旋压,加工成形变壁厚双锥角锥形件的方法。同时给出了考虑偏镦正弦律强力旋压等壁厚和变壁厚锥形件毛坯的设计模型。 相似文献
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喷管锥段是火箭发动机能量转化和推力向量控制机构,一般采用剪切旋压加工。采用ABAQUS有限元软件,建立了高强铝合金7A52锥形件剪切旋压模型;采用单一变量法,分析了旋压间隙、旋轮进给比、旋轮圆角半径对锥形件剪切旋压壁厚差的影响,为锥形件的制造提供一定的指导。 相似文献