铝合金管材超低温介质压力胀形行为  

Behavior of ultra-low temperature medium bulging for aluminum alloy tube

作　　者：凡晓波 王旭刚 陈险烁 苑世剑 Fan Xiaobo;Wang Xugang;Chen Xianshuo;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》2021年第4期1-6,共6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：针对铝合金复杂异形管件常温成形易开裂的难题,利用铝合金在超低温下伸长率与硬化指数同时提高的双增效应,提出了铝合金异形管件超低温介质压力成形方法。通过建立管材超低温介质压力胀形装置,测试了6061铝合金管材在液氮温度(-196℃)条件下的胀形性能;结合数值模拟,分析了铝合金管材在超低温条件下的自由胀形行为。结果表明:铝合金管材在超低温(-196℃)条件下,胀形性能显著提高,膨胀率由常温下的17.4%增加至34.5%,提高了近1倍;超低温下铝合金管材的硬化能力同样提高,变形更均匀;相同变形阶段,随着硬化指数n值的增加,自由胀形变形区的极限应变和应变梯度均逐渐降低。For the problem of easy cracking for aluminum alloy complex special-shaped tube,an ultra-low temperature medium bulging method was proposed by the double-increasing effect of simultaneous increase of elongation and hardening index for aluminum alloy at ultra-low temperature,and the bulging performance of 6061 aluminum alloy tube under the condition of liquid nitrogen temperature(-196 ℃)was tested by establishing the device of ultra-low temperature medium bulging for tube.Then,the corresponding free bulging behavior of aluminum alloy tube at ultra-low temperature was analyzed by experiment and FEM.The results show that the bulging performance of aluminum alloy tube is significantly improved under ultra-low temperature condition(-196 ℃),and the expansion rate is increased from 17.4% at normal temperature to 34.5% which is increased by nearly onetime.Furthermore,the hardening ability of aluminum alloy tube at ultra-low temperature is also enhanced,and the deformation is more uniform.At the same deformation stage,the ultimate strain and strain gradient of free bulging deformation zone are gradually reduced with the increasing of hardening index value of n.

关 键 词：铝合金异形管件 超低温介质压力胀形 胀形性能 变形均匀性 

分 类 号：TG394[金属学及工艺—金属压力加工]