INVESTIGATION OF THE TERNARY PHASE-DIAGRAM OF MECHANICALLY ALLOYED FECUAG

The structural and magnetic properties of mechanically alloyed Fe-Cu-A g at room temperature have been investigated using Fe-57 Mossbauer spe ctroscopy, x-ray diffraction and differential scanning calorimetry. Th e elements are naturally immiscible, but through prolonged and energet ic ball milling (70 hours at 600 rpm) one can make metastable alloys, the structure of which depends on the elemental composition. In the bi nary Cu-Ag and Fe-Cu systems, crystalline single-phase solid solutions result, whereas in Fe-Ag the alloying is limited, with the product a mixture of elemental particles. In the ternary system it is possible t o produce copper- and silver-rich single-phase fee alloys, but not the equivalent bcc iron-based structure. As the proportions of the three elements become more equal, the resulting structure becomes highly dis ordered or amorphous. The composition range of this amorphous phase is different to that observed in sputtered Fe-Cu-Ag systems.