GRAIN-GROWTH AND TEXTURE IN RAPIDLY SOLIDIFIED FE(SI) 6.5 WT-PERCENT RIBBONS

The dependence of structural properties of Fe(Si) 6.5 wt.% ribbons on annealing treatments has been investigated in the temperature range 70 0-1300 degrees C. Two different annealing methods, respectively charac terized by slow (conventional) and fast (infrared) heating rate, have been considered. It is found that abnormal grain growth takes place ab ove a threshold temperature, which depends on the type of annealing, w ith the average grain size attaining a maximum value around 200 mu m. Such a growth is conducive to a cube-on-face (100) crystallographic te xture after conventional annealing, whereas after the infrared treatme nt a cube-on-edge (110) texture is observed. The texture development i s here discussed in terms of competition between grain boundary and su rface energy minimization, with attention devoted to the role of the p resence of oxygen on the surface energy of (100) and (110) crystallogr aphic planes. (C) 1997 Elsevier Science S.A.