| 摘要 |
High density, generally microscopically homogeneous corrosion-resistant chromium-uranium metal alloys for ammunition use (particularly for spherical pellets or shot) can be made from U238 or an isotopic mixture high in U238 (such as "depleted uranium") and at least about 10 atomic % chromium. The alloys can also contain one or more metals of Group VIII, first triad, of the Periodic Table, and a variety of other elements used, for example, in making ferrous metals. Major factors to be considered in formulating the alloy are density, melting point or melting range, passivity or chemical or biological inertness, resistance to segregation in the molten phase and upon rapid cooling (chromium-poor phases or regions being particularly undesirable), and compensation for any loss of free chromium due to formation of intermetallic or other forms of combined chromium. The uranium content in the alloy is preferably less than 70 atomic %. Rapid cooling of the chromium-uranium or chromium-uranium-Group VIII metal melt, e.g. by the shot tower technique, avoids undesirable segregation effects which can detract from corrosion resistance. The shot tower may optionally contain a non-oxidizing atmosphere.
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