ALLOYING EFFECTS ON THE ELECTRONIC-STRUCTURE OF CHROMIUM

Alloying effects on the electronic structure of Cr metal were investig ated in order to obtain useful information for alloy design. The elect ronic structures were calculated by the DV-X alpha molecular orbital m ethod, and two alloying parameters were determined theoretically. One was the d-orbital energy level Md and the other was the bond order Bo for various alloying elements M in Cr. By using these parameters, allo ying behaviour was elucidated successfully. For example, the solidus t emperature of binary Cr-M alloys showed a positive correlation with th e bond order Bo. Also, the solubility limits of alloying elements in t he Cr solid solution at 873 K were associated with Md and Bo. Furtherm ore, the appearance of intermetallic compounds, e.g. the sigma-phase a nd the Laves phase in the Cr binary system was predictable with these alloying parameters. The present results were shown to be useful as a guide for designing high-performance chromium-based alloys.