Experimental and theoretical prediction of Copper-Nickel nano-phase diagram

Copper and Nickel alloys form binary isomorphous system with a symmetric lens shaped curve formed by solidus and liquidus. This shape and size of the solidus and liquidus curves are altered by the particle size. This effect is greatly enhanced if the particle size is less than 100 nm. In the present work, phase diagram is predicted for nanoparticles considering Copper and Nickel and is compared with the experimental results. Copper and Nickel nanoparticles were procured and were characterized for the particle morphology and size using TEM, FE-SEM and XRD. The nanoparticles were also subjected to DSC analysis to find the melting point. The nanoparticles were blended in a high energy ball-mill for various compositions. The blending was carried out for different time intervals and was characterized using XRD to find the effective alloying time. The blended nanoparticles after effective alloying were subjected to DSC analysis to experimentally determine the solidus and liquidus points for various compositions. Phase diagram was determined experimentally and was compared with the theoretical prediction. GTE model and E&E models were used to predict the phase diagram for nanoparticles and was compared with the experimental results. It was found that the E&E model acurately predicts the nano phase diagram for Cu-Ni system with an error of 2% for 89 wt% Cu-11 wt% Ni alloy.