Deformation behavior of Mo5SiB2 at elevated temperatures

During high-temperature compression tests on Mo5SiB2, the deformed microstructure varies with the temperature, strain rate and strain, and their changes have profound effects on the deformation behavior. At 1200 °C, the plastic deformation is provided by dislocation glide on potential slip planes, such as {1 1 0} and {0 0 1}. Due to the limitation of less activated slip systems, the specimens rupture when compressed to the strain of ~3% at 1200 °C and 1.67×10−4 s−1. With temperature increasing to 1400 °C, the activation of more independent slip systems increases the deformation capability of the alloy. However, there is an increasing tendency for slip planes to be of an unexpected type (e.g. {1 4 3} and {5 2 3}) as a function of decreasing strain rate and increasing temperature, which is related to dislocation climb. Moreover, dynamic recovery or recrystallization is easy to occur under the conditions of heavy deformation (like 25% strain) and slow strain rate (like 1.67×10−4 s−1), showing the decrease in the dislocation density and flow stress.