Phase constitution and microstructure of Ce-Fe-B strip-casting alloy

The strip-casting technique plays an important role in fabricating high coercivity sintered magnet. In this paper, we investigate the phase constitution and the microstructure of rapidly solidified Ce-Fe-B alloy fabricated by strip-casting. We find that the Ce₂Fe₁₄B phase coexists with Fe, Fe₂B, and CeFe₂ phases in the Ce-Fe-B strips. The eutectic structure consisting of Fe and Fe₂B is encased in Ce₂Fe₁₄B grains, which is blocked by the CeFe₂ grains at triple junctions, indicating that the microstructure of Ce-Fe-B strip is characteristic of a peritectic solidification. Thermal analysis indicates that the large supercooling of Ce₂Fe₁₄B results in the residual Fe and Fe₂B. The microstructural optimization in Ce-Fe-B strips without Fe and Fe₂B could be achieved by a heat treatment of 1000℃.