SURFACE SEGREGATIONS IN EMBRITTLED (FexNi1-x)z (PyB1-y)1-z GLASSY RIBBONS BY AUGER ELECTRON SPECTROSCOPY

We have searched for a correlation between surface segregation of constituent elements and thermal embrittlement in (Fe0.5Ni0.5)1-x (ByP1-y)x glassy ribbons. Surface segregations are investigated by A.E.S. on as quenched and annealed glassy ribbons Fe16Ni64P14B6 and (Fe½ Ni½)1-xBx (x = 0.17, 0.20, 0.23). Embrittlement is observed after annealing at 573K during 2 h on all the samples except the Fe41.5Ni41.5B17. We obtain large segregation of metalloïd elements on all the annealed samples indicating, no direct correlation with the mechanical behaviour.