铝白铜合金热变形行为及热加工图的研究

Study on Hot Deformation Behavior and Hot Processing Map of Aluminum White Copper Alloy

利用Gleeble-3500热模拟机在变形温度750~950℃、应变速率0.01~10 s-1进行了等温热压缩实验,得到铝白铜合金的真应力-真应变曲线。在实验结果的基础上,采用应变、应变速率和变形温度耦合的改进Johnson-Cook(J-C)模型,分析了合金的流动应力行为。用模型对其进行了拟合分析,建立并验证了流动应力的本构方程。结果表明,J-C本构模型能够准确地描述加工温度和应变速率对材料流动应力的影响,在低应变速率下预测结果与实验数据吻合良好。结合热加工图和微观组织可以确定,铝白铜合金的最佳变形温度为820~920℃,应变速率为5~10 s-1。

The isothermal compression tests were conducted for aluminum white copper with the temperature range of 750-950℃ and strain rates range of 0.01-10 s~(-1)at Gleeble-3500 simulator,and the true stress-true strain curves of the aluminum white copper alloy were obtained.Based on the experimental results,the modified Johnson-Cook(J-C) model coupled with strain,strain rate and deformation temperature was adopted to analyze the flow stress behaviors of the alloy.It was fitted and analyzed with the model.The constitutive equation of flow stress was established and verified.The results show that the J-C constitutive model can accurately describe the effect of processing temperature and strain rate on the flow stress of the material,and the predicted results at low strain rates are in good agreement with the experimental data.Combining the thermal processing map and the microstructure,it can be determined that the optimal deformation temperature of the aluminum white copper alloy is 820-920℃,and the strain rate is 5-10 s~(-1).