1. Powder making and reduction: Firstly, the highly pure ammonium rhenate crystal particles were pretreated and crushed to -100~300 mesh; Then low temperature reduction was carried out in hydrogen, the reduction temperature was controlled at 230-350 ℃, and the reduced products were reprocessed, and then ground and broken through -100~150 mesh sieve. Then sufficient secondary reduction was carried out in hydrogen and the reduction temperature was controlled at 800-950 ℃ to obtain a pure rhenium powder with an oxygen content of less than 0.1%, a particle size of 2-6 m and a purity of >99.95%.
2. Billet: Adopt detachable die to press and form, so that the billet can be separated from the die and transferred safely without any force; At the same time, a lubricant of 1.5-3% (mass percentage) was added into the powder to prepare the billet with a thickness of 5-15mm and a Boson ratio greater than 16.
3. Sintering deformation: After dewaxing and pre-firing, the billet is sintered at a high temperature under the protection of hydrogen. The sintering temperature is controlled at 2000-2340 ℃ until the density reaches more than 95% of the theoretical density, the thickness is 4-12 mm, and the sintered billet is uniformly crystallized and fine.
4. Rolling deformation: Cold rolling process is adopted at room temperature, and the pass deformation is strictly controlled at 8-15%; After each step of deformation, high-temperature annealing treatment was conducted in hydrogen. The annealing temperature was 1500-1800 ℃, and the annealing time was 30-120 min to eliminate the working hardening phenomenon and control the uniform and fine crystallization. Then the next step of rolling was carried out. Finally, after annealing treatment, the finished rhenium flake was obtained.
