Abstract
The hot deformation behavior of bimodal TiC/AZ61 magnesium matrix composites was investigated using hot compression tests at temperatures ranging from 250 °C to 400 °C and strain rates ranging from 10−4 to 0.1 s−1. Microstructure evolution and flow instability behavior are investigated. The results show that the bimodal TiC/AZ61 composite contains two instability and safe zones, and its optimum process parameter ranges of hot working were determined as 260–320 ℃ and 0.0009–0.03 s−1. Both Continuous Dynamic Recrystallization (CDRX) and Discontinuous Dynamic Recrystallization (DDRX) mechanisms occur during hot deformation. In the low temperature and high strain rate zone (250–290 ℃, 0.01–0.1 s−1), instability is caused by incomplete DRX and twins, whereas in the high temperature and low strain rate region (340–400 ℃, 0.0001–0.003 s−1), it is associated with abnormal grain growth, which is caused by the occurrence of grain boundary migration from coarse grain to fine grain. This study advances our understanding of hot deformation mechanisms in bimodal magnesium matrix composites and facilitates the development of these materials for a wide range of industrial applications.
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