Enhanced Ms of Fe-rich Fe-B-Cu amorphous/nanocrystalline alloys achieved by annealing treatments

The effects of Fe content and annealing temperature on the microstructure, thermal stability and soft magnetic properties of Fe-rich Fe83.5+xB15-xCu1.5 (x = 0.5, 1.0, 1.5, 2) alloys were investigated. The results show that when the Fe content is going up to 85%, alloys still have the capability of forming a single amorphous phase. After that, glass-forming ability (GFA) is weakened and crystalline phase appears. In terms of thermal stability of alloys, the increase in Fe content is beneficial to obtain a larger crystallization temperature interval (ΔTx = 144.4 ℃), which is conducive to the process of heat treatment and the preparation of amorphous/nanocrystalline soft magnetic materials. The optimum annealing treatments (430 ℃×10 min) can yield the high saturation magnetization (Ms) of 208 emu/g, which is comparable to the one of alloy Fe-Si 3 wt%.