Study on the composition effect upon the microstructure development in Cu-Fe alloys prepared using a W-wire method

The present work focuses on the microstructure development in Cu-Fe alloys during solidification with a minimum contact area using W-wire. The effect of undercooling and composition on the microstructure development of the above alloys is systematically investigated using a multi-modal characterization technique such as X-ray tomography, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Electron Backscatter Diffraction (EBSD). The experimentally determined undercooling in the Cu-rich alloys is in the range of 230-250 degrees C (pure Cu: 230 degrees C, Cu75Fe25: 245 degrees C.) whereas, the undercooling obtained in Fe-rich alloys is between 70 degrees C and 93 degrees C (pure Fe: 93 degrees C, Cu25Fe75: 70 degrees C). In the case of Cu50Fe50 composition, the undercooling is 115 degrees C which is in the intermediate range. The effect of undercooling on the solidification morphology, microstructure development and phase separation is clearly presented in the present study. In addition, Cu rich alloy (Cu75Fe25) exhibits a planar microstructure with a relatively discernible phase separation between the Cu and Fe rich phases. Whereas in case of Cu50Fe50 and Cu25Fe75alloy, the presence of Fe in the Cu rich phase side is observed.