摘要
为了研究Al-Zn-Mg-Cu铝合金的高温本构方程及加工工艺窗口,首先,使用Gleeble-3500热模拟试验机对Al-Zn-Mg-Cu铝合金进行了等温热压缩实验,研究了其在变形温度为623~773 K、应变速率为0.001~1 s^(-1)条件下的高温流变特性。其次,利用高阶梯度信息建立了该合金的高精度新本构方程,并基于该方程推导了热加工图的计算模型。最后,通过典型区域的金相实验验证了热加工图的合理性。热压缩曲线表明,在低应变速率条件下,该铝合金的应力随着应变的增加先迅速上升后缓慢下降最终趋于稳定;在高应变速率条件下,应力先迅速上升后急剧下降而后缓慢上升最后再缓慢下降至稳定。偏导数分析表明,lnσ与T之间采用2阶逼近、lnσ与T之间采用1阶逼近,可构建精度高、参数少的本构方程。热加工图及金相分析表明,稳定的热加工窗口为:应变速率为0.001~0.035 s^(-1)、变形温度为623~773 K。
To investigate the high-temperature constitutive relationship and hot processing window of Al-Zn-Mg-Cu aluminum alloy,firstly,the isothermal hot compression test of Al-Zn-Mg-Cu aluminum alloy was conducted by thermal simulation machine Gleeble-3500,and its high-temperature rheological properties under the deformation temperature of 623-773 K and the strain rates of 0.001-1 s^(-1) were studied.Secondly,a new high-precision constitutive equation of the alloy was established by high-order gradient information,and the calculation model of the hot processing map was derived based on this equation.Finally,the rationality of the hot processing map was verified by metallographic tests in typical regions.The hot compression curves indicate that under low strain rate conditions,the stress of the aluminum alloy first rises rapidly and then slowly decreases and finally stabilizes with the increasing of strain.Under high strain rate conditions,the stress first rises rapidly and then drops sharply,followed by a slow increase,and finally slowly decreases to stability.Partial derivative analysis reveals that the second-order approximation between lnσand lnε·and the first-order approximation between lnσand T can construct a constitutive equation with high accurate and few parameters.Hot processing map and metallographic analysis demonstrate that the stable hot processing window is the strain rate of 0.001-0.035 s^(-1) and the deformation temperature of 623-773 K.
作者
徐槿昊
龙亚
Xu Jinhao;Long Ya(School of Rail Transit,Zhejiang Institute of Communications,Hangzhou 311112,China)
出处
《锻压技术》
北大核心
2025年第6期259-267,共9页
Forging & Stamping Technology
基金
浙江省教育厅一般科研项目(Y202352134)。
