Hot deformation behavior and microstructure evolution of the Al-2.5at.%Nd alloy

Al-Nd alloys are crucial sputtering target materials for suppressing hillock formation in Al thin films within display devices. To optimize the hot processing parameters and elucidate the microstructure evolution mechanisms of Al-2.5at.%Nd alloy, hot compression tests were conducted using a Gleeble-3800 thermal simulator over a temperature range of 300-450 °C and strain rates of 0.001-1 s−1. An Arrhenius-type constitutive model incorporating the Zener-Hollomon parameter (Z) was established, demonstrating high correlation (R2 = 0.977) and low prediction error (AARE = 6.61%), enabling accurate flow stress prediction. Processing maps based on the Dynamic Materials Model identified two optimal processing windows: 0.001-0.008 s−1 / 360-430 °C and 0.003-0.05 s−1 / 430-450 °C. Quantitative modeling of dynamic recrystallization (DRX) kinetic using the Yada model revealed that the DRX volume fraction increased with decreasing strain rate and increasing deformation temperature. Electron backscatter diffraction and transmission electron microscopy characterizations and analyses confirmed that lower strain rates promoted DRX nucleation and growth, reduced dislocation density, and refined grain size. This study provides significant insights and guidance for optimizing the hot processing of Al-Nd alloys.