Methods of treating metal nanocrystals are provided. In embodiments, such a method comprises exposing metal nanocrystals comprising a metal and characterized by at least one twinning boundary therein, to a plating solution comprising a reducing agent and coating metal cations comprising a different metal, under conditions to form a coating of the different metal on surfaces of the metal nanocrystals via electroless deposition by chemical reduction of the coating metal cations, thereby providing coated metal nanocrystals. Methods of forming bulk nanostructured metal alloys from the coated metal nanocrystals are also provided.