摘要
研究了电塑性效应对5A90铝锂合金成形极限的影响。首先,通过不同温度和不同应变速率的通电单向拉伸实验和等温无电单向拉伸实验,获取了材料的应变硬化指数n和应变速率敏感指数m。然后,采用M-K理论,将Lorgan-Hosford屈服准则和Backoften硬化方程引入理论推导中,利用Newton-Raphson迭代法进行求解计算,求解得到5A90铝锂合金在电塑性影响下的成形极限图。最后,通过不同宽度试样的单向拉伸实验对成形极限图的左手侧曲线进行了实验,结果与预测相吻合。研究结果表明:相比普通热成形,电塑性效应对5A90铝锂合金成形极限的提高效果更加明显。
The influence of electroplastic effect on forming limit of 5A90 Al-Li alloy was investigated.At first,the strain hardening exponent n and strain rate sensitivity exponent m were obtained by conducting electroplastic tension tests and isothermal tension tests at different temperatures and strain rates.Then the forming limit diagram(FLD)of 5A90 Al-Li alloy under the effect of electroplastic was predicted by using M-K model which introducing Lorgan-Hosford yield criterion and Backoften hardening equation theoretical derivation,and the method of Newton-Raphson iteration.Finally,the left side curves of the predicted FLD was verified by uniaxial tension tests of sheet specimens with different widths,and the result is in accordance with the prediction.The research results show that the forming limit of 5A90 Al-Li alloy is improved more obviously by the electroplastic effect than that by the conventional hot forming.
作者
邓恒
董湘怀
DENG Heng;DONG Xiang-huai(National Engineering Research Center of Die&Mold CAD,Shanghai Jiao Tong University,Shanghai 200030,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期114-119,共6页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51635005
51775335)
关键词
5A90铝锂合金
电塑性效应
应变硬化指数
应变速率敏感指数
成形极限图
5A90 Al-Li alloy
electroplastic effect
strain hardening exponent
strain rate sensitivity exponent
forming limit diagram
