Although the Wollaston process of producing platinum metal from platinum powder is regarded as the birth of modern powder metallurgy (1808-1815), it was the pioneering work of W.D.Coolidge on the production of ductile tungsten wires in 1909-1913 which led to its first commercial application. Over the years, only few changes were made in the industrial production of tungsten metal. Powder metallurgy is still today the main route in tungsten and tungsten alloy manufacture. Unlike other refractory metals, such as Zr, Hf, Nb, or Ta, melting technology has assumed no industrial importance for metal production, since the very high temperature, necessary for melting, and the resulting coarser microstructure of the “as cast” material make further processing both difficult and costly.
Powder metallurgy comprises two steps: compaction and sintering.
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