A method of forming in-situ composites of metallic alloys comprising an amorphous phase are provided. The method generally comprising the steps of transforming a molten liquid metal at least partially into a crystalline solid solution by cooling the molten liquid metal down to temperatures below a “remelting” temperature, then allowing the solid crystalline metal to remain at temperatures above the glass transition temperature and below the remelting temperature such that at least a portion of the metal remelts to form a partially amorphous phase in an undercooled liquid, and finally subsequently cooling the composite alloy to temperatures below the glass transition temperature.