Effect of Tb Doping on the Microstructure and Magnetic Properties of Quenched Fe₇₃Ga27-xAlx Alloys

In this experiment, quenched FeSUB73/SUBGaSUB27-x/SUBAlx and (FeSUB73/SUBGaSUB27-x/SUBAlx)SUB99.8/SUBTbSUB0.2/SUB alloys (x=0, 1 , 2, 3, 4, 5) were respectively prepared, and the effects of 0.2 at% Tb doping on the microstructure and magnetic properties of FeSUB73/SUBGaSUB27-x/SUBAlSUBx/SUB alloys were studied. The results show that the phase structure of FeSUB73/SUBGaSUB27-x/SUBAlx and (Fe73Ga27-xAlx)SUB99.8/SUBTbSUB0.2/SUB alloys are mainly composed of A2 phase, but (FeSUB73/SUBGaSUB27-x/SUBAlx)SUB99.8/SUBTbSUB0.2/SUB alloys also contain a small quantity of Tb2Fe17 phase. After Tb doping, the lattice constant of alloys is descended, altering the microstructure of alloys, and the orientation of (FeSUB73/SUBGaSUB27/SUB)SUB99.8/SUBTbSUB0.2/SUB and (Fe73Ga25Al2)SUB99.8/SUBTbSUB0.2/SUB a lloys a long the crystal direction [100] is increased saliently. The Al element in (FeSUB73/SUBGaSUB27-x/SUBAlx)SUB99.8/SUBTbSUB0.2/SUB alloy exists in the form of deposited phase, and Tb₂FeSUB17/SUB phase is formed at grain boundaries after Tb doping, thus improving the magnetostrictive property of alloys. The λ∥ and Vickers hardness of FeSUB73/SUBGaSUB27-x/SUBAlx alloys are in the range of 52-64×10SUP-6/SUP and 316.13-328.68 HV, separately. After Tb element doping, the λ∥ and Vickers hardness of the alloy reach the maximum 88×10SUP-6/SUP and 408.49 HV at x=2 at%, which is individually increased by 69.23 % and 29.21 % compared with Fe73Ga25Al2 alloy. And its Hc keeps low, which can reduce magnetization powers and losses. Therefore, (FeSUB73/SUBGaSUB27-x/SUBAlx)SUB99.8/SUBTbSUB0.2/SUB alloy gives consideration to the excellent magnetic properties and high Vickers hardness, having the most practical production value in the two series of alloys.