Research on thermal compression behavior and microstructural evolution mechanism of 2A14 aluminum alloy

Abstract

The hot deformation behavior was probed through hot compression experiments with a range of temperature between 250 °C and 470 °C and strain rates ranging from 0.01 to 5 s⁻¹. Simultaneously, the microstructural evolution was revealed employing electron backscatter diffraction (EBSD). Based on the hyperbolic sine function and dynamic material model, the constitutive equation was established and the critical conditions for dynamic recrystallization (DRX) were determined. The results indicate that the Z parameter (parameter temperature and strain rate compensation factor) exerts a notable influence on the hot deformation behavior and microstructure evolution. At higher lnZ values (low temperature or high strain rate) situations, the DRX volume percentage is relatively low. As ln Z decreases, the DRX process accelerates, leading to a significant rise in the fraction of high-angle grain boundaries (HAGB). Meanwhile, the main DRX mode of alloys driven by discontinuous dynamic recrystallization (DDRX), accompanied by continuous dynamic recrystallization (CDRX). The alloy undergoes complete DRX while subjected to high temperatures and rapid strain rates (450 °C, \(\dot{\varepsilon } = 5{\text{s}}^{{ - 1}}\), ln Z = 23.75). With increase in deformation, the texture along grain boundaries transitions gradually from the P {001} < 122 > orientation to the Brass {011} < 211 > and S {123} < 634 > orientations.

Graphical abstract