Molybdenum and alloys

In 1778, Karl Wilhelm Scheele put an end to the confusion over the nature of molybdenite and graphite, by showing that molybdenite (MoS ₂ ), when subjected to nitric attack at high temperatures, left a white residue, which he then identified as an acid oxide, which we know to be molybdic anhydride.

In 1782, P. J. Hjelm separated the metal, in the form of a fine powder, by heating the oxide with charcoal, and gave it the name molybdenum. He was unable to melt this powder, and it wasn't until 1893 that H. Moissan succeeded in melting molybdenum by heating a mixture of molybdenum dioxide and charcoal in an electric furnace. The resulting metal contained numerous impurities and was 92% to 96% molybdenum.

The first industrial use of molybdenum was the addition of this element to armor steels, in 1894, at the Schneider plants in Le Creusot. The industrial production of pure molybdenum in massive form became possible in 1909, when W. D. Coolidge demonstrated that the powder metallurgy technique he had developed for the manufacture of tungsten filaments was applicable to molybdenum. Molybdenum wire, used in the manufacture of incandescent lamps, was the first major industrial application. The use of wire expanded into metallization and, along with ribbon, the manufacture of radio lamps and electrical contacts. These applications accounted for the bulk of molybdenum consumption until the outbreak of the Second World War.

In the 1950s, to satisfy new applications in a wide variety of industrial sectors, the production of larger, higher-performance semi-finished products led to a technological transformation in manufacturing processes: electrofused molybdenum (Climax Molybdenum 1953), isostatic pressing, accompanied by the production of higher-purity molybdenum and the development of precipitation-hardening and solid-solution-hardening alloys.