PURPOSE: To enhance the dispersibility of ThO2 and to easily obtain a recrystallized structure by adding an aqueous soln. of sodium nitrate to tungsten oxide powder in a specified ratio, drying them in the air at ≤100°C, reducing the powder in a hydrogen atmosphere at a specified temp. for a secified time, and manufacturing thorium-tungsten by a known method using the resulting powder as a material.
CONSTITUTION: To tungsten oxide powder is added an aqueous soln. of sodium nitrate by 0.2W5%, and they are dried in the air at ≤100°C. This powder is reduced in a hydrogen atmosphere at 700W900°C for 30W60min to decompose sodium nitrate as well as to reduce tungsten oxide. Thorium-tungsten is then manufactured by carrying out known processes such as formation of an ingot using the resulting fine powder as a material, heating to a high temp. by electrifying, forging and wire drawing in succession.
SHIMOMURA SHIGEO
TAKAKURA HIROSHI
