摘要：

13. ABSTRACT (Maximum 200 woras) The primary goal of the proposed research was to study and develop alloying concepts for understanding intermetallic alloys as derived from a first principles quantum mechanical approach. Thus, a major part of our effort was to study and determine ductilizing effects of alloying elements in several intermetallic compounds and to work closely with experimental efforts to evaluate the applicability of the theoretical approach to alloy design. Specifically, highly precise all-electron quantum mechanical electronic structure methods were applied to the study of a number of material problems in order to obtain from first principles information of relevance to alloy stability on the design of structural materials. Using our recently developed stateof-the-art all-electron self-consistent total energy methods which gives precise solutions of the local density equations, fundamental information was sought about the structural and electronic properties of these alloys in order to predict stable and metastable phases and how alloying effects bonding, crystal ordering and crystal symmetry. The first principles approach used here addresses questions of a metallurgical nature, such as phase stability, crystal structure, equilibrium lattice constant and mechanical properties including the effect of atomic relaxation.

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