Alloys of Uranium

Alloys of uranium and aluminium are readily obtained by the addition of a mixture of urano-uranic oxide and aluminium powder to a bath of molten aluminium; by heating a mixture of uranic oxide and aluminium by the aluminothermic process; or by electrolysis of the fused double chloride, K₂UCl₆, using aluminium electrodes. By the aluminothermic process, Guillet obtained products of definite composition: U₂Al₃, hard lustrous cubic crystals, and UAl₃, fine needle-shaped crystals.

Many alloys of uranium and iron, containing up to 70 per cent, of uranium, have been obtained by reduction of uranium oxide with carbon and iron. After purification, the alloys contain about 2 per cent, of carbon, silicon, vanadium, and sometimes aluminium. Ferrouranium alloys with more than 20 per cent, uranium exhibit pyrophoric properties which increase with increasing content of uranium. In Colorado the alloys are obtained as by-products in the extraction of radium from carnotite, and contain 35 to 40 per cent, of uranium and 1.5 to 4 per cent, of carbon. If less than 2 per cent, of carbon is present the alloys are tough, but with more carbon they are brittle; the presence of silicon increases the brittleness. The carbon is usually present as carbides of uranium, iron, and vanadium, and such alloys are decomposed by water. Uranium does not form solid solutions with iron. Uranium steels containing ferro-uranium of low carbon content possess similar properties to tungsten steels.

According to Stavenhagen and Schuchard the following alloys have been prepared by the method of alumino-thermic reduction: UFe, UMn, UFeMn, UCo, UMo, and UMoCrTi.