Effect of Sm on dynamic recrystallization of Mg-8Gd-0.5Zr alloy during hot compression

Hot Deformation Behavior of Non-Alloyed Carbon Steels

“…After heating and defined holding time at the deformation temperature, the specimens were deformed by uniaxial compression. The strain value was determined to be a multiple of 1.3•ε crDRX , while the critical strain necessary to induce dynamic recrystallization of ε crDRX was determined according to relation (16), resp. according to the procedure described in Section 4.2.…”

“…After reaching the steady state, i.e., the stress σ ss , there is a balance between the softening and strengthening processes, and with increasing strain, the stress in the area IV.th does not change (see Figure 1) [12,14,15]. Depending on the chemical composition of the investigated materials and the chosen method of calculating the critical strain ε crDRX , it should apply that ε crDRX = (0.09 ÷ 0.8)•ε p [13,[16][17][18]. The critical strain required to induce dynamic recrystallization increases with increasing strain rate and decreasing temperature [12][13][14]16].…”

“…Depending on the chemical composition of the investigated materials and the chosen method of calculating the critical strain ε crDRX , it should apply that ε crDRX = (0.09 ÷ 0.8)•ε p [13,[16][17][18]. The critical strain required to induce dynamic recrystallization increases with increasing strain rate and decreasing temperature [12][13][14]16]. The kinetics of dynamic recrystallization is also affected by the grain size of the investigated steel.…”

“…The initial finer grain-sized structure significantly accelerates the occurrence of DRX because the existing fraction of grain boundaries already determine the density of nucleation sites. The number of available nucleation sites will be reduced by reducing the total area of grain boundaries in a given material volume, which will be reflected in the course of DRX [4,16,17,19,20]. Coarse-grained structure materials (e.g., in the as-cast state) show a small total grain boundary area (compared to fine-grained materials), and thus, intragranular nucleation becomes the prevailing process.…”

“…For the purposes of research of the deformation behavior of metallic materials, continuous isothermal uniaxial compression tests are very suitable, which are most often performed on the Gleeble type simulators, whose products are flow stress curves [22][23][24]. The information about maximum flow stress and kinetics of dynamic recrystallization of a given material can be obtained from these flow stress curves [2,4,16,22,25,26]. In addition, these flow stress curves can be described by mathematical models, which can then be used as one of the material's input characteristics for a mathematical simulation using the finite element method.…”