Thermal stability and crystallization of Fe<inf>89.8</inf>Ni<inf>1.5</inf>Si<inf>5.2</inf>B<inf>3</inf>C<inf> 0.5</inf> amorphous alloy

Abstract

The thermal stability and crystallization of the Fe89.8Ni1.5Si5.2B3C0.5 amorphous alloy in non-isothermal as well as in isothermal conditions were studied. It was shown that the amorphous alloy was stable up to a temperature of 753 K when a multi-step structural transformation began. Initially an α-Fe phase was formed, followed by a Fe2B phase at temperatures over 813 K. Kinetic parameters, the activation energy (Ea) and the pre-exponential factor (ln A), for both crystallization steps were determined as Ea = 486.3 kJ mol-1 and ln A (A [min-1]) = 72.7 for first step and Ea = 446.3 kJ mol-1 and ln A (A [min-1]) = 63.7 for second step according the Kissinger method and as Ea = 499.9 kJ mol-1 and ln A (A [min-1]) = 88.1 for first step and Ea = 460.8 kJ mol-1 and ln A (A [min-1]) = 79.2 for second step according the Ozawa method. © 2009 Elsevier B.V. All rights reserved.