Industrial-scale manufacturing experience of titanium beryllide block for DEMO blanket application

For the first time, the TiBe12 blocks have been manufactured by powder metallurgy using industrial equipment at the Ulba Metallurgical Plant. Such blocks will be used for neutron multiplication in the helium-cooled breeding blanket for the EU DEMO fusion reactor. The vacuum annealing of a cold-pressed composite of Be and Ti powders at 600-1275 degrees C approved the conditions for TiBe12 synthesis. After hot isostatic pressing at 1150 degrees C, a single-phase TiBe12 structure was formed, but the sample fragmented into several pieces. These beryllide pieces were used to manufacture TiBe12 powder. Vacuum hot pressing of the obtained powder resulted in a solid titanium beryllide workpieces of empty set150 mm x 170 mm. Electrical discharge machining and waterjet cutting were used to machine the external and internal surfaces in accordance with the design requirements. The obtained block has a density of 98.3 % of the theoretical density of TiBe12. Microstructural analysis revealed a bimodal grain size distribution with grains of 5-10 mu m and 20-40 mu m. Electrical conductivity and thermal expansion coefficient of TiBe12 are similar to other beryllides. To mimic the pulsed operating conditions in DEMO, a sample of titanium beryllide was rapidly heated to 900 degrees C and cooled with a rate of 12 K/s. After 50 cycles, the sample had no cracks or severe surface oxidation.