Al-Cu-Li合金热变形特性与位错密度模型构建

Thermal Deformation Characteristics and Dislocation Density Model Construction of Al-Cu-Li Alloy

通过等温压缩试验,研究热轧态Al-Cu-Li合金在温度为390~480℃、应变速率为0.01~1s^(-1)下的流变行为。基于热压缩流动应力数据构建了峰值应力Arrhenius本构模型,其平均相对误差绝对值(AARE)为4.612%。基于该模型数据,采用K-M模型以及Taylor关系式建立了耦合温度、应变速率、峰值应力、峰值应变的位错密度模型。该模型AARE值为5.926%,具有较高精度,为准确描述Al-Cu-Li合金在热变形过程中的位错密度演变提供参考。

The isothermal compression experiments of hot rolled Al-Cu-Li alloy at temperature range of 390~480℃ and strain rate range of 0.01~1 s^(-1) were carried out on GLEEBLE-3500 isothermal simulator.The peak stress Arrhenius constitutive model was con⁃structed based on the isothermal compression flow stress data,and its average absolute relative error(AARE)is 4.612%.Based on the model,a dislocation density model of coupling temperature,strain rate,peak stress and peak strain was constructed based on K-M model and Taylor relationship,which has an AARE-value of 5.926%,indicating a high prediction precision.This model provides a reference for accurately describing the dislocation density evolution of Al-Cu-Li alloy during thermal deformation.