Structural Metallurgy of Refractory Metals

Abstract

Applying the somewhat arbitrary criterion of a melting temperature exceeding 2000 K. sixteen transition metals, belonging to Groups 4 to 10 of the periodic table of elements, have been designated as refractory metals in this paper. Crystal structure data pertinent to these metals have been provided and the polymorphic transformations (temperature-induced and pressure-induced) exhibited by some of them described. Temperature -pressure phase diagrams of these elements have been discussed and a few representative examples presented. A compilation of data pertaining to some important physical properties of refractory metals is included for ready reference.

Keywords:

• Refractory metals
• Transition metals
• Melting temperatures
• Crystal structures
• Polymorphism
• Phase diagrams