DSC AND X-RAY STUDY OF HYDROGENATED FE79B14SI7 AND FE60CO25B15 AMORPHOUS-ALLOYS

The influence of electrolytic hydrogenation on the thermal stability a nd on the Curie points of planar flow cast Fe79B14Si7 and Fe-60Co25B-1 5 amorphous metallic alloys was studied by means of DSC, thermomagneti c gravimetry and X-ray diffraction. The hydrogen desorption from the a morphous ribbons is revealed in DSC as an endothermic peak in the temp erature range 350 to 490 K, preceding two exothermic crystallization p eaks. An activation energy for hydrogen desorption of 20.7 +/- 1.2 kJ/ mol has been calculated using Kissinger's method. An increase of the C urie point of Fe79B14Si7 metallic glass by 7 to 8 K was observed durin g the initial stages of hydrogenation, followed by a decrease after a given hydrogenation time. The influence of hydrogen on thermal stabili ty and crystallization of both glasses was found to be insignificant.