Thermal behavior of several Fe-Ni alloys prepared by mechanical alloying and rapid solidification

Summary

Several Fe-Ni-P-Si alloys were produced in an amorphous state by mechanical alloying and rapid solidification. Thermal behavior of the as prepared alloys was analyzed and compared with identical alloys stored during 1 and 2 years. During annealing time, several exothermic processes related to the structural relaxation were detected at low temperature and with further crystallization at high temperature. As increasing the storage time, the powdered samples were relaxed at lower temperatures. The activation energy, E, of the main crystallization process varies between 2.7 and 4.7 eV at.^-1. The E values obtained remains similar with the storage time. Small contamination from the milling tools was found. Furthermore, powdered alloys are more sensible to oxidation processes than as quenched ribbons.