Effect of Strain Rate on the Microstructure and Texture Evolution of the ZK60 Alloy Sheets

Abstract

The dynamic recrystallization (DRX), precipitation and texture evolution of the ZK60 alloy sheets rolled at 300 °C with different strain rates were studied, and the effects of texture on the plasticity were also clarified. The DRX grain sizes at five strain rates (5–25 s−1) are 1.4 μm, 1.2 μm, 1.8 μm, 2.4 μm and 2.8 μm, respectively, while the DRX volume fractions are 35.8%, 75.0%, 82.0%, 88.0% and 93.0%, respectively. The maximum intensity values of the (0002) texture are 7.91, 8.22, 7.64, 5.76 and 5.34 at five strain rates, respectively. The strongest (0002) texture is observed at the strain rate of 10 s−1, which is related to the relatively low DRX volume fraction and the precipitation density. The tensile strength (UTS) and yield strength (YS) increases firstly and then decreases, while the elongation (EL) gradually increases with increasing the strain rate, suggesting that the plasticity of the alloy sheet can be improved by decreasing the basal texture intensity and increasing the dispersion degree of the basal texture. The optimal comprehensive mechanical properties are obtained at the strain rate of 10 s−1, with UTS of 358 MPa, YS of 291 MPa and EL of 21.5%. The DRX grain sizes at five strain rates (5–25 s−1) are 1.4 μm, 1.2 μm, 1.8 μm, 2.4 μm and 2.8 μm, respectively, while the DRX volume fractions are 35.8%, 75.0%, 82.0%, 88.0% and 93.0%, respectively. The maximum intensity values of the (0002) texture are 7.91, 8.22, 7.64, 5.76 and 5.34, respectively. The tensile strength (UTS) and yield strength (YS) increases firstly and then decreases, while the elongation (EL) gradually increases with increasing the strain rate, and the optimal comprehensive mechanical properties are obtained at 10 s−1, with UTS of 358 MPa, YS of 291 MPa and EL of 21.5%