Molecule-like chemical units in metallic alloys

Each conventional alloy has its own specific compositions but the compositional origin is largely unknown due to our insufficient understanding about chemical short-range ordering in alloy, particular, solid-solution state. In present paper, of metallic alloys are discussed and formulated, by unveiling basic moleculelike structural units solid solutions. Friedel oscillation theory, which describes partial charge screening behavior solutions, henceforth ordering, applied pin down ideal alloys. We propose that, at a composition, atoms self-assemble into an ideally ordered structure consisting residing nearest-neighbor shell (denoted as cluster) plus those next outer glue atoms), can be formulated [cluster](glue atoms). This simplified version short-range-order represents smallest charge-neutral mean-density zone (termed “chemical units”) regarded ‘molecules’ Accordingly, corresponding molecule-like formulas for face-centered-cubic (FCC), hexagonal close-packed (HCP), body-centered cubic (BCC) structures analyzed equations obtained identify FCC For instance, well-known ?-brass Cu-30Zn [Zn-Cu12]Zn4. Examples aluminum alloys, superalloys stainless steels also illustrated, demonstrating versatility model interpret chemically complex