Rhenium Properties

The element is silvery white with a metallic luster; its density is exceeded only by that of platinum , iridium, and osmium, and its melting point is exceeded only by that of tungsten and carbon. It is nearly twice as dense as lead (21 g/cm3) and extremely rare (1 pound of rhenium per 1000 million pounds of earth!!!). Nonetheless, the total annual U.S. production of Re is almost half a ton. It is used as a trace alloying element for metal components that are subject to constant friction.

The usual commercial form of the element is powder, but it can be consolidated by pressing and resistance-sintering in a vacuum or hydrogen atmosphere. This process produces a compact shape in excess of 90 percent of the density of the metal.

Annealed rhenium is very ductile, and can be bent, coiled, or rolled. Rhenium is used as an additive to tungsten and molybdenum -based alloys to impart useful properties.