Effect of Fe content on microstructure and magnetic properties ofNdFe10.25TiNb0.25N/α-Fe permanent magnet alloy

Abstract:

The effect of Fe content on NdFe_10.25TiNb_0.25/Xwt.%α-Fe permanent magnet alloy was studied in terms of microstructure and magnetic properties. Alloy ingot is composed of α-Fe phase, 1:12 phase and Nd-rich phase, Fe content increases, α-Fe phase content increases, and 1:12 phase content decreases. The grain size of the thin strip decreases gradually with the increase of Fe content, and Fe2Ti phase is produced. The contents of Fe₂Ti phase and Nd-rich phase decrease gradually with the increase of Fe content. When X≥15, the thin strip only has 1:12 phase and a-Fe phase, and the average grain size is reduced to less than 60 nm. After nitriding, the average grain size is reduced by 15%-20%, and the magnetic properties are obviously improved. When X=15, the obtained nitrided alloy thin strip has better magnetic properties, coercivity is 1010 Oe, saturation magnetization is 130.7 emu/g, which is 25% higher than that when X=0, and saturation magnetization is 12% higher. After bonding, the maximum magnetic energy product decreases first and then increases, and reaches the highest value at X=15, reaching 4.03 MGOe, which increases by 40% compared with 2.88 MGOe at X=0. The nitriding alloy thin strip at X=15 has good structural stability at high temperature, and maintains structural stability below 360℃, which has great application potential at high temperature.

Key words:NdFe_10.25TiNb_0.25/α-Fe alloy; Fe content; Melt fast quenching; Microstructure; Magnetic property