Formation of nanocrystalline phases during decomposition of amorphous Ni-Palloys by continuous linear heating

Differential scanning calorimetry (DSC), powder diffraction and high-resolu tion X-ray diffraction (XRD), and transmission electron microscopy (TEM) in vestigations have been performed on melt-quenched amorphous Ni-P alloys wit h compositions of 18 to 22 at.% P. The calorimetric results revealed differ ent crystallization routes during linear heating below, at and above the eu tectic point (19 at.% P) but with the same general transformation scheme as reported previously for electrodeposited and electroless Nl-P amorphous al loys. The composition dependence of the activation energy of the crystalliz ation and the heats evolved during the structural transformations were dete rmined from DSC measurements. The average grain size was derived from XRD l ine broadening and important information on the crystallization products an d their microstructure could be revealed also from the TEM studies. All the se findings will have special significance when analysing the results of is othermal annealing experiments to be described in a forthcoming paper.