Alloys of Niobium

Investigation into the formation of alloys of niobium with other elements has hitherto been scanty, and even where alloying is known to take place the conditions for the alloy formation and the properties of the products have received little attention. Niobium appears to alloy with iron in all proportions; the alloy containing 90 per cent, of iron and 10 per cent, of niobium is extremely hard.1 Niobium, usually in conjunction with tantalum because of the difficulty of their separation, can be used for incorporation into special steels.

Aluminium-niobium alloys are best produced by the Goldschmidt process. A product which contains about 3 per cent, of aluminium is harder than glass or quartz; its density is 7.5. A brittle alloy of chromium and niobium is obtained by fusing green chromium oxide and niobium together in the electric furnace.

Alloys of niobium and tantalum with nickel and zirconium have also been prepared. It is claimed that the latter can be heated to whiteness in air without oxidation or vaporisation.

Potassium, sodium, magnesium, and mercury can be distilled over niobium without formation of alloys; arsenic, antimony, and tellurium do not form alloys below 500° to 600° C.