| The effect of minor addition of Al and Nb on bulk glass formability in Cu50Zr50 alloy is investigated. Quenching rate effect was followed comparing the results obtained on ribbons and on different sections of cone-shaped ingots. The phase mixture has been clarified for each alloy, combining structural, microstructural and composition analyses. A fully amorphous phase has been found in ribbons, whereas only for (Cu50Zr50)96Al4 a bulk metallic glasses has been obtained. Minor Al addition hinders the formation of the CuZr martensite phase. The effect of composition on the glass forming abilty has been evaluated with emprical parameters, but only the calculation of driving forces for nucleation of crystal phases, using the CALPHAD method, may explain the results. |
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