Thermodynamic Properties and Phase Equilibria in the Ternary Cu-Pb-Fe System

Using experimental data available in the literature, two binary systems, namely Cu-Pb and Fe-Pb were recalculated. Next, accepting Cu-Fe phase diagram assessment as given by Ansara and Jansson, the ternary Cu-Fe-Pb system was analyzed. Calculated equilibrium lines and thermodynamic functions are compared with existing experimental data. Good agreement was found between the calculated diagram and the experimental results. Having the system optimized, functional dependences of the logarithms of the activity coefficients on temperature and concentrations for Cu, Fe and Pb in the liquid solution are given.

Metastable Crystalline Phases Synthesized by Ion Beam Mixing in Some Nb-Based Binary Metal Systems

ABSTRACTIn the Nb-rich Nb-Fe(Co,Ni) multilayered films, two metastable crystalline (MX) phases of hep and fee structures were formed by room temperature 200 keV xenon ion mixing. The phase formation was through a two-step transition, Le. a first shearing of bcc—>hcp and then a sliding of hep—>fcc. The free energy curves of the observed MX phases were calculated and included into the free energy diagram together with those of the terminal solid solutions, the amorphous phase and the equilibrium intermetaШc compounds. An independent comparative thermal annealing experiment was conducted with the corresponding as-deposited multilayers and the results certified the emerging sequence of the MX phases being exactly the same as the calculated diagram predicted. Moreover, a crystallographic model was figured out for the bec—>hcp—>fcc transition and the resultant lattice parameters agreed well with the experimental ones.