Effects of pre-compression modes on mechanical properties and fatigue behaviors of rolled ZK60 magnesium alloy

The research investigated the microstructure, monotonic mechanical properties, and fatigue behaviors of ZK60 magnesium alloy treated with single-pass pre-compression and combined pre-compression. The study found that combined pre-compression significantly improved mechanical strength in both the transverse and rolling directions compared to the single-pass method. Due to the randomized texture and intricate interwoven grain structures, the combined pre-compression method significantly mitigated the anisotropy observed in samples treated with single-pass pre-compression. Both pre-compression techniques enhanced the fatigue life of the ZK60 magnesium alloy. Samples subjected to combined pre-compression exhibited fatigue performance comparable to those treated with single-pass pre-compression. Additionally, there was a clear negative correlation between the fatigue life of the three samples and the magnitude of the mean stress. The abundance of pre-existing dislocations in the combined pre-compression processed samples helped in reducing the trend towards cyclic hardening. In contrast to single-pass pre-compression, the combined pre-compression method effectively reduced twinning activities and promoted the participation of basal slip during cyclic loading, leading to a more symmetrical hysteresis loop.