The application of refractory metals encompasses areospace and nuclear industries, fusion energy, high energy physics, electonics, energy conversion and chemical processing. Metals belonging to groups Va and VI of the periodic table, which form the refractory metals family, are characterised by many common features. They have the same crystal structure (bcc), high melting points, similar chemical interactions with other elements, generally high ductile-brittle transition temperatures and a similar alloying behaviour. Because of these similarities, the metallurgy of these metals can be developed on a common foundation and handled in a unified manner. The common features of the chemical processing methods and physical and mechanical behaviours of this group of metals have never before been covered in a single book. The book will begin with an account of the interatomic bonding and physical properties of these metals. The different classes of phase diagrams that these metals exhibit and their interactions with interstitial elements will be summarized. The problem of high ductile-brittle transition temperatures and the general principles of ductilization will also be discussed. The book will bring out the fact that in the case of these metals different physical phenomena like deformation, diffusion, recovery, recrystallisation, creep and oxidation stand on a common ground and bear a create deal of similarity. Therefore the same principles can be applied for alloying, strengthening, ductilising and protecting these metals. The book will also cover recent developments in coating technology, intermetallics and composites related to refractory metals. This book is anup-to-date, single source account of physical and chemical metallurgy. It will be invaluable for undergraduate and graduate students, research workers and professionals in the field of high temperature metals and materials. A thorough summary of both the chemical and the physical metallurgy of the bcc refractory metals from a single, reliable source. Unifies the field of refractory metals.