| 摘要 |
A method of extruding fine grain natural uranium suitable for reactor fuel, comprises heating a pre-formed natural uranium slug to 1000-1100 DEG F., extruding the slug at a pressure sufficient to cause the transformation of the product emerging from the extrusion die into the beta phase, and rapidly cooling it. This enables extrusion to take place in the alpha phase with automatic transformation into beta phase and the rapid cooling produces a fine grain structure and obviates further heat treatment. Machined hollow slugs heated in an argon atmosphere are extruded into a tube by a high-speed ram actuated by pressure gas, and having a machined carbon dummy block which eliminates any discard. A lubricant, consisting of an aluminium graphite suspension in a quick evaporating organic solvent, is sprayed on to the slug and the pre-heated extrusion tools. The extruded tube emerging from the die is trapped in a catch tube stuffed with rock wool and is rapidly cooled by compressed air or water. Specific examples are given.
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