冲击载荷下Al-Mg-Si-Cu铝合金的变形行为及本构模型

Deformation behavior and constitutive model of Al-Mg-Si-Cu aluminum alloy under high speed impacting

使用分离式霍普金森压杆(SHPB)对Al-0.59Mg-0.58Si-0.2Cu(质量分数/%)铝合金进行室温下、应变率为(800~5 200)s-1的高速冲击试验,分析其变形行为,并确定Johnson-Cook本构方程。结果表明:Al-Mg-Si-Cu铝合金在室温高速冲击变形过程中,应力不随应变率增加而增加;当应变率为800、2 500、3 100 s-1,应变为0.08时,随着应变率的增加,织构类型发生改变,平均斯密特因子和应力减小;确定Al-Mg-Si-Cu铝合金的J-C本构方程,本构拟合结果与试验结果吻合。

High speed impact experiments were carried out on Al-0.59 Mg-0.58 Si-0.2 Cu(mass fraction/%)aluminum alloy using split Hopkinson pressure bar(SHPB)over strain rate ranges from 800 s-1 to 5 200 s-1 at room temperature. The deformation behaviors were studied and the Johnson-Cook constitutive equation was obtained. The results show that the flow stresses of Al-Mg-Si-Cu aluminum alloy do not increase with increasing strain rate. As the strain rates are 800,2 500 and 3 100 s-1,and with the strain is 0.08,the texture type changes with strain rate increasing,the average Schmid factors decrease and flow stresses decrease. The Johnson-Cook constitutive equation for Al-Mg-Si-Cu aluminum alloy was determined and the fitting results well match with the experimental results.