2219铝合金差厚球壳梯度超低温拉深成形规律  

Gradient ultra-low temperature deep drawing law of 2219 aluminum alloy spherical shell with differential thickness

作　　者：凡晓波 刘洋[1] 邬方兴 苑世剑 Fan Xiaobo;Liu Yang;Wu Fangxing;Yuan Shijian(School of Mechanical Engineering,Dalian University of Technology,Dalian 116024,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]大连理工大学机械工程学院,辽宁大连116024 [2]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《锻压技术》2023年第5期155-161,共7页Forging & Stamping Technology

基　　金：国家重点研发计划项目(2019YFA0708804);中央高校基本科研业务费专项资金资助(DUT20ZD101)。

摘　　要：针对铝合金差厚球壳薄厚过渡区易集中变形而导致开裂的难题,利用超低温条件下铝合金伸长率与硬化指数显著提高的双增效应,提出铝合金差厚球壳梯度超低温拉深成形新方法;通过超低温拉深成形工艺装置,在梯度超低温条件下试制了直径为Φ200 mm的2219铝合金差厚球型曲面件;结合数值模拟,分析了差厚球壳梯度超低温拉深成形规律,揭示了薄厚过渡区的变形协调机制。结果表明:超低温下高硬化能力可转移薄厚过渡区的集中变形,并且具有足够的塑性变形能力来承受由厚区约束导致的薄区变形增大;在梯度超低温下,厚薄比为2.0的差厚板的成形性能显著提高,相对常温提高76.4%。梯度超低温成形差厚球壳具有巨大潜力,可为大型差厚薄壁曲面件成形提供新路径。For the problem of cracking due to concentrated deformation in the thin-thickness transition zone of aluminum alloy spherical shell with differential thickness,a novel method of gradient ultra-low temperature deep drawing for aluminum alloy spherical shell with differential thickness was proposed by utilizing the double-increase effect of the significant increase in the elongation and hardening index of aluminum alloy under ultra-low temperature condition,and the 2219 aluminum alloy spherical curved surface parts with differential thickness and the diameter of@200 mm under the gradient ultra-low temperature condition was trial-produced by ultra-low temperature deep drawing process device.Then,combined with numerical simulation,the gradient ultra-low temperature deep drawing law of spherical shell with differential thickness was analyzed,and the deformation coordination mechanism in the thin-thickness transition zone was revealed.The results indicate that the high hardening capacity at ultra-low temperature can transfer the concentrated deformation in the thin-thickness transition zone,and has sufficient plastic deformation capacity to withstand the increased deformation in the thin zone caused by the constrant in the thick zone.Under the gradient ultra-low temperature,the formability of differential thickness sheet with a thickness ratio of 2.0 is significantly improved,which is 76.4%higher than that at normal temperature.Thus,the differential thickness spherical shell obtained by gradient ultra-low temperature forming has great potential,which can provides a new way for the forming of large differential thickness thin-walled curved surface parts.

关 键 词：铝合金 差厚板 梯度超低温拉深成形 成形性能 变形均匀性 

分 类 号：TG386[金属学及工艺—金属压力加工]