The insight effect of texture components on the recrystallization behavior of MoRe alloy

Abstract

Molybdenum alloys are promising materials for high-temperature gas-cooled reactor fuel cladding due to their excellent performance at elevated temperatures, favorable mechanical properties, corrosion resistance, and low neutron absorption cross-section. However, their high melting point and inherent hardness require annealing to improve processability. This study investigates the effects of vacuum annealing on the microstructure and texture evolution of rotary swaged MoRe alloys. The as-swaged alloy exhibits a fibrous structure with elongated grains along the axial direction (AD). Annealing at 1200 °C results in a bimodal microstructure, with both deformed and recrystallized grains, indicating a partially recrystallized (PRX) state. Furthermore, annealing at 1300 °C leads to a completely recrystallized (CRX) microstructure. The recrystallization mechanism is primarily driven by subgrains coalescence. The texture of the rotary swaged MoRe alloy is dominated by a strong 〈101〉//AD fiber texture, accompanied by a weaker 〈001〉//AD texture. After recrystallization, the intensity of the <101>//AD texture decreases, while the <001>//AD texture becomes more prominent. These texture changes suggest that the <001>//AD texture promotes recrystallization, whereas the <101>//AD texture hinders it. The evolution of the recrystallization texture is attributed to the preferential growth of <001>//AD grains and stress-driven grain rotation. These findings provide valuable insights for optimizing the heat treatment process of rotary swaged MoRe alloys.