Temperature-dependent creep aging behavior of 2A14 aluminum alloy
Wenfang Yu, Lihua Zhan, Yongqian Xu, Kai Chen, Youliang Yang, Lingzhi Xu, Nanhui Peng, Bolin Ma, Cong Liu, Zanchong Chen
Abstract
The creep deformation behavior, aging hardening response and microstructure evolution of 2A14 aluminum alloy (Al-4.81wt%Cu-0.66wt%Mg-0.97wt%Si) at different temperatures have been systematically investigated by creep test, tensile test, transmission electron microscopy and differential scanning calorimetry. The results show that the total creep strain and steady-state creep rate significantly increase with increasing temperature in the range of 408 K–458 K, while the creep behaviors at the optimum aging temperature of 433 K have shortest primary creep stage and lowest stress sensitivity. Pinning of dislocations by the dense and fine Q′ and θ′ phases precipitated in the alloy creep-aged at 433 K, which contributes to obtaining the best mechanical properties. Also, the primary creep deformation mechanism at different aging temperatures has been discussed. A reference temperature describing the degree of the interaction between aging precipitates and dislocations is introduced into the hyperbolic-sine creep model. The creep strain predicted through the temperature-dependent creep model is in good agreement with the experimental data. The research can provide theoretical support for the temperature-varying creep age forming application in the 2A14 aluminum alloy components.