Nanocomposite Nd-Fe-Ti-B magnets produced by melt spinning and flash annealing

We have attempted to fabricate a nanocomposite Nd-Fe-Ti-B magnet. Flash-lamp rapid annealing treatments were performed for melt-spun ribbons to obtain the α-Fe/Nd2Fe14B composite microstructure, and the evolution of magnetic properties by the annealing was studied by vibration sample magnetometer (VSM). It was found that the magnetic properties were improved by relatively short-time annealing at the temperatures near the crystallization temperature. Further higher-temperature and longer annealing treatments resulted in deterioration of the magnetic properties. For the selected samples, recoil curves were measured to analyze the spring-back behaviors. Transmission electron microscopy (TEM) was performed to investigate the microstructural factors for the deterioration of the magnetic properties. The relation between the variation of the magnetic properties (coercivity, saturation magnetization and recoil permeability) and the microstructural factors were discussed.