Synthesis and characterization of metastable Ag-B solid solutions

Mechanical alloying (MA) was applied to Ag-B immiscible binary systems by ball milling elemental Ag and B powders. The microstructural characterization of the milled powders was carried out by XRD and TEM. The results show that face-centered-cubic (FCC) Ag-B solid solutions are formed and that the maximum ratio of B to Ag is 4 : 1. The structure evolution of Ag-B solid solution during ball milling indicates that the formation of Ag-B solid solution may be divided into two stages, which are mainly substitutional and interstitial solutions separately. The decomposition of the as-milled granules under the irradiation of electron beam is observed by TEM, which reveals that the solid solutions are metastable.