Glass formation and soft magnetic properties of novel Fe-rich Fe-B-Ti-Zr bulk metallic glasses

Abstract

Composition design is an important issue concerning the development of bulk metallic glasses (BMGs), especially applicable Fe-based bulk metallic glasses (BMGs). In this work, new quaternary Fe77B18TixZr5-x (x = 1–4) BMGs were developed by promoting metastable transformation in solidification process. Their glass formation, thermal and soft magnetic properties have been investigated. Thermal analysis proves that the combined additions of Ti and Zr in the alloys have significant advantage in improving the glass forming ability (GFA). However, the alloy with best GFA does not show the optimal thermal performance, and such inconformity in MGs was usually neglected previously. We further explain the origin of the improvement in GFA and the inconformity between GFA and thermal properties by investigating the phase evolution of the crystalline alloys. Proper combined additions of Ti and Zr can promote the precipitation of metastable Fe23B6 phase, which is advantageous to GFA as the diverse crystallization pathways reflect different crystallization resistances in solidification. Owing to the high Fe content, the amorphous ribbons exhibit high saturation induction of over 1.3 T.