Abstract: To understand the structure, phase precipitation behavior and magnetic properties of ternary La2Fe14B and Ce2Fe14B alloys, the effects of wheel speed (10—50 m/s) of melt spinning and heat treatment on these alloys were investigated. The results show that, as for pun alloys, the hard magnetic 2∶14∶1 phase could not be obtained in La2Fe14B alloys, but it could be formed in Ce2Fe14B alloys. The phases of α-Fe and La mainly precipitated in La2Fe14B ribbons at 10 m/s. However, the hard magnetic 2∶14∶1 phase precipitated in Ce2Fe14B ribbons at 10 m/s and 20 m/s. With the increase of wheel speed, the content of amorphous phase increased. For annealed La2Fe14B alloys, the results showed that α-Fe and La phases mainly precipitated from the amorphous matrix, and liquid La-rich regions and α-Fe phases could coexist. However, in the annealed Ce2Fe14B alloys, α-Fe phase precipitated first followed by the appearance of 2∶14∶1 phase and grain growth. In addition, the amorphous La2Fe14B alloy had higher cure temperature than Ce2Fe14B alloy, and it started to precipitate α-Fe phase at lower temperature. As a result, relatively good hard magnetic properties with a certain coercivity could be obtained in Ce2Fe14B alloys due to the precipitation of hard magnetic 2∶14∶1 phase. This work will be valuable for exploring the La or Ce based rare earth permanent magnets.
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2018, Vol. 32 
