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 25°C to 900°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≤ 37.4 (Zis the Zener–Hollomon parameter), DRX can occur in SD specimens with a critical temperature for the DRX onset of ~650°C and a thermal activated energy (Q) of 313.5 kJ·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 700°C,Q is 351.7 kJ·mol?1, and the occur-rence condition of DRX is lnZ≤ 40.1. The zig-zagging of GB morphology can significantly reduce the nucleation energy at the GBs; as a re-sult, DRX nucleation occurs more easily in SD specimens than in PD specimens.