Effect of texture on high temperature deformation behavior at high strain rates in a Mg-3Al-1Zn alloy

The effect of specimen orientation, or texture on high temperature deformation behavior at a high strain rate of 10(3) s(-1) was investigated in an extruded Mg-3Al-1Zn alloy rod with (10 (1) over bar 0) fiber texture. Uniaxial compression test data were obtained along two specimen directions (longitudinal and transverse directions). The temperature dependence of yield stress was small up to 673 K for both directions, indicating that a diffusion process is not rate-controlling at such a high strain rate. The alloy exhibited strong plastic anisotropy at 10(3) s(-1) from room temperature to 673 K. For the transverse specimens, the yield stress was lower than that for the longitudinal specimens. In addition, plastic deformation occurred preferentially in the radial direction of the extruded rod. These results suggest that basal slip is the dominant deformation mechanism for the transverse specimens. On the other hand, strong temperature insensitivity of flow stress as well as concave flow curves observed in the longitudinal specimens suggested the prevalence of twinning. (C) 2009 Elsevier B.V. All rights reserved.