Effect of compression direction on the dynamic recrystallization behavior of continuous columnar-grained CuNi10Fe1Mn alloy

The dynamic recrystallization (DRX) behavior of continuous columnar-grained (CCG) CuNi10Fe1Mn alloy was investigated by hot compression along the solidification direction (SD) and perpendicular to the solidification direction (PD). Specimens were compressed to a true strain of 0.8 at temperatures ranging from 25A degrees C to 900A degrees C and strain rates ranging from 0.01 to 10 s(-1). The results indicate that DRX nucleation at grain boundaries (GBs) and DRX nucleation at slip bands (SBs) are the two main nucleation modes. For SD specimens, C-shaped bending and zig-zagging of the GBs occurred during hot compression, which made DRX nucleation at the GBs easier than that at the SBs. When lnZ a parts per thousand currency sign 37.4 (Z is the Zener-Hollomon parameter), DRX can occur in SD specimens with a critical temperature for the DRX onset of similar to 650A degrees C and a thermal activated energy (Q) of 313.5 kJ center dot mol(-1). In contrast, in PD specimens, the GBs remained straight, and DRX nucleation occurred preferentially at the SBs. For PD specimens, the critical temperature is about 700A degrees C, Q is 351.7 kJ center dot mol(-1), and the occurrence condition of DRX is lnZ a parts per thousand currency sign 40.1. The zig-zagging of GB morphology can significantly reduce the nucleation energy at the GBs; as a result, DRX nucleation occurs more easily in SD specimens than in PD specimens.