METASTABLE CRYSTALLIZATION PHASES IN THE AMORPHOUS ALLOY METGLAS-2826A

It is proved experimentally by transmission electron microscopy that the first crystallization of METGLAS® 2826A is a two-stage process, called MSI and MSII, rather than one-stage as described by Chang and Sastri. The details of MSI and MSII were investigated (structure, composition, morphology, activation energies) and discussed in terms of kinetics. MSI is controlled by small-scale diffusion involving metalloid depletion and, therefore, decelerated (√t-type) reaction kinetics; MSII grows linearly with t because it is entirely interface-controlled. Certain differences in the results in comparison with Chang and Sastri's have been explained. © 1979 Chapman and Hall Ltd.