Evolution of microstructure and texture of moderately warm-rolled pure tungsten during annealing at 1300 °C

The mechanical behavior, microstructure and texture evolution were investigated during isothermal annealing at 1300 °C of pure tungsten moderately warm-rolled to 67% thickness reduction. The degradation of the mechanical properties is characterized by hardness testing. The microstructure and texture evolution during heat treatment were characterized by Electron Backscatter Diffraction. During annealing of the moderately warm-rolled tungsten, recrystallization occurred first, quickly followed by relatively slow grain growth. The recrystallized volume fractions determined from hardness measurements and microstructural characterization were essentially the same. The evolution of the grain sizes during recrystallization was analyzed independently for deformed and recrystallized grains. Quantitative texture analysis showed that the overall texture strength is enhanced after recrystallization. As recrystallization strongly affects the mechanical properties of tungsten, such insights in the annealing behavior of warm-rolled tungsten plates are valuable for an understanding of their performance as potential plasma-facing materials in future fusion reactors.