Fully understanding the performance of nanocrystalline ternary Pr-Fe-B alloys with three typical phase constitutions

Pr ₂Fe ₁₄B phase exhibit similar intrinsic magnetic properties as Nd ₂Fe ₁₄ B with even higher magnetic anisotropy field. Here we investigated the magnetic properties, exchange interaction, and corrosion resistance of melt-spun ternary Pr-Fe-B alloys with three typical compositions including Pr ₁₀Fe ₈₄B ₆, Pr ₁₂Fe ₈₂B ₆, and Pr ₁₄Fe ₈₀B ₆. The hard magnetic Pr ₂Fe ₁₄B phase is present in all alloys, while the α-Fe and RE-rich phases are additionally present in Pr ₁₀Fe ₈₄B ₆ and Pr ₁₄Fe ₈₀B ₆ alloys, respectively. Under optimum wheel speed of melt spinning, uniform single-phase behavior has been obtained for all alloys, which gives optimal hard magnetic properties. Based on exchange interaction behavior analysis, the nanocomposite Pr ₁₀Fe ₈₄B ₆ alloy and single phase Pr ₁₂Fe ₈₂B ₆ alloy show more uniform reversal domain nucleation behavior during demagnetization process. Importantly, Pr-Fe-B alloys show significant advantages over Nd-Fe-B alloys at cryogenic temperature. The hard magnetic properties increase with reducing temperature and extremely high coercivity has been obtained at 100 K. Pr ₁₀Fe ₈₄B ₆ alloy exhibits not only better low temperature stability but also much higher corrosion resistance than the Pr ₁₄Fe ₈₀B ₆ and Pr ₁₂Fe ₈₂B ₆ alloys. The existence of soft phase can improve the anti-corrosion properties, while the RE-rich phase is not advantageous to corrosion resistance although it enhances the coercivity.