Interatomic Bond, Crystal Structure, and Principal Physical Properties of Refractory Metals

Abstract

Many earlier data on the properties of metals are now out of date, having been determined on insufficiently pure metals. In recent years, all the refractory transition metals (titanium, zirconium, hafnium, vanadium, niobium, tantalum, rhenium, pure iron, manganese, chromium, molybdenum, tungsten), refractory metals of the platinum group (osmium, ruthenium, iridium, and others), lithium, beryllium, semiconductors (germanium, silicon, boron, high-purity carbon), and the radioactive metals (uranium, thorium, plutonium) have become available for research. The rare-earth metals of the cerium subgroup (lanthanum, cerium, neodymium, praseodymium), metals of the yttrium subgroup, as well as scandium and yttrium are being produced in everincreasing quantities. They are no longer just rare laboratory specimens, but industrial metals for alloying and for application as alloy bases. In the 50' sand 60' s of this century, scientific and production workers created a new combination of the media of the chemical technology of the production of pure substances and vacuum metallurgy: ion exchange chromatography, the iodide method, electrolysis, distillation, vacuum or argon-arc, electron-beam, plasma, and laser melting, vacuum zone refining using different sources of heat, pressure treatment and welding in a vacuum or in an atmosphere of inert gases, vacuum annealing, use of getters, protective envelopes, coatings, and so forth.