Effect of vacuum annealing and heating-cooling cycle annealing on the soft magnetic properties at room-and high-temperatures for nanocrystalline FeCoAlSiBCuNb alloy

摘要

Effect of vacuum annealing and heating-cooling cycle annealing on the soft magnetic properties at room- and high-temperatures for (Te_(0.9)Co_(0.1))_(72.7-) Al_(0.8)Si_(13.5)B_9Cu_1Nb_3 alloy was investigated by the temperature dependence of initial permeability (μ_i-T curves). The crystallization behavior and microstruc-tural evolution of alloy with the increase of annealing temperature were studied by means of differential scanning calorimeter (DSC) and X-ray diffraction (XRD). After vacuum annealing at 617 °C for 0.5 h, the μ_i, can reach 30,300 and maintain more than 1000 until 640 °C because of larger crystalline volume fraction (V_(cry)) of 81.9% and smaller intergranular amorphous layer (A) of 0.930 nm, which is more excellent than that of other Fe-Co-Al-Si-B-Cu-Nb alloys annealed at their optimum temperatures. In addition, the crystallized interval temperature (△T_x) of 158 °C, superior to Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 and (Fe_(0.9)Co_(0.1))_(73.5)Si_(13.5)B_9Nb_3Cu_1 alloys ever reported, is conducive to precipitating the bcc α-(Fe,Co,Si) and Fe_3(Si,Co,Al) soft magnetic crystalline phases and improving thermostability of alloy.