摘要
为了降低残余应力,传统工艺流程一般采用先成形、后振动时效的方法,而现将低频振动施加到成形过程中,以此来缩短制造工艺流程,并获得具有较低残余应力的冲压件。采用高精度伺服压力机对6082铝板进行振动辅助弯曲实验,设置了振幅、频率和下压速率3个变量,分别测量振动辅助弯曲成形后试样弯曲圆弧表面的残余应力,并使用EBSD表征内弯面处的平均取向差,使用XRD测量弯曲圆弧截面的平均位错密度,得到不同振动参数对残余应力和位错密度的影响规律。实验发现:振动辅助弯曲成形能够有效降低残余应力,最高可降低36.96%;残余应力随着振幅的增大先降低、后升高,随着频率的增大先增大、后保持不变,随着下压速率的增大而增大。通过对低频振动辅助弯曲过程进行模拟和分析,并结合位错相关理论解释了振动辅助弯曲成形影响残余应力的微观机理。
In order to reduce residual stress,the traditional process often uses the method of forming first and then vibration aging. Now,the low frequency vibration is applied to the forming process to shorten the manufacturing process flow and obtain stamping parts with low residual stress. Therefore,the vibration assisted bending experiment of 6082 aluminum plate was carried out by high-precision servo press,and three variables of amplitude,frequency and depression rate were set up. Then,the residual stress on the curved arc surface of sample after vibration assisted bending was measured,and the average misorientation at the inner curved surface was characterized by EBSD and the average dislocation density of the curved arc section was measured by XRD to obtain the influence laws of different vibration parameters on residual stress and dislocation density. The results show that vibration assisted forming effectively reduces the residual stress up to 36. 96%,and the residual stress decreases first and then increases with the increasing of amplitude,increases first and then remains unchanged with the increasing of frequency,and increases with the increasing of depression rate. Finally,through the simulation and analysis of low frequency vibration assisted bending process,combined with the dislocation related theory,the micro-mechanism of vibration assisted forming affecting residual stress is explained。
作者
王宇飞
周芃
邓磊
王新云
Wang Yufei;Zhou Peng;Deng Lei;Wang Xinyun(State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《锻压技术》
CAS
CSCD
北大核心
2020年第10期27-34,共8页
Forging & Stamping Technology
基金
国家自然科学基金资助项目(51725504)
中央高校基本科研业务费专项资金资助(2018KFYYXJJ027)。
关键词
6082铝合金
振动辅助弯曲
残余应力
振动参数
位错密度
6082 aluminum alloy
vibration assisted bending
residual stress
vibration parameters
dislocation density
