Influence of thermal treatment on structure and microhardness of Fe <inf>75</inf>Ni<inf>2</inf>Si<inf>8</inf>B<inf>13</inf>C<inf>2</inf> amorphous alloy

Abstract

Correlation between hardness of amorphous Fe75Ni 2Si8B13C2 alloy and thermally induced structural transformations has been investigated by measuring microhardness in a series of samples heated at different temperatures from 25 to 1000 °C. The alloy has a relatively high hardness in the amorphous state, due to its chemical composition involving silicon, boron and carbon. As the alloy begins to crystallize, microhardness increased and reached a plateau in 500-650 °C temperature region, due to formation composite structure involving the small nanocrystals of α-Fe(Si) and Fe2B phases dispersed in the amorphous matrix. After treatment at higher temperatures, the nanocomposite structure is replaced by a more granulated structure, leading to decline in microhardness. © 2011 Elsevier Ltd. All rights reserved.