Influence of phase transformation on interfacial activity and bend sensitivity of rapidly quenched Fe77.5Si7.5B15/Co72.5Si12.5B15 bilayered magnetostrictive ribbons

Abstract

Rapidly quenched bilayer magnetostrictive ribbons have been prepared and characterized to investigate phase transformations, interfacial activity and their potentiality as bend sensors. The bilayer ribbons were processed in a way to make the positively magnetostrictive layer Fe77.5Si7.5B15 as the free surface while negatively magnetostrictive Co72.5Si12.5B15 layer as the one in contact with the quenching copper wheel. Elemental concentration profiles obtained through electron probe microanalysis (EPMA) revealed synergistic variation in Fe and Co content at the interface. Devitrification process was also observed from atomic migrations and combinations influencing the interface width. Configuration of the bent layers showed interesting bending parameter output which could be further enhanced through stress relaxation. A detrimental effect of devitrification on bend sensitivity of rapidly quenched bilayers was also displayed.