Volume 11 of group IV presents phase diagrams, crystallographic and thermodynamic data of ternary alloy systems. The subvolume E deals with refractory metal systems, with part 1 considering selected systems from Al-B-C to B-Hf-W. At ambient pressure the equilibria of each individual ternary system are discussed as functions of temperature yielding spatial diagrams whose sections and projections are displayed. The phase equilibria are described in terms of liquidus, solidus and solvus projections, isothermal, vertical and quasibinary sections. Data on invariant equilibria are generally given in the form of tables and reaction schemes. The volume forms a comprehensive review and rigorous systematization of the presently available data. For each system the often conflicting literature and contradictory information has been thoroughly evaluated by a team of experts, MSIT, and can thus be presented in a standard format. Back to the year 1900 the literature has been reviewed, implying possible reinterpretations from today's state of knowledge, and incorporated in the volume. The tables and diagrams are preceded by descriptive commenting texts.