High Performance Plasma Sprayed Nd2fe14B Permanent Magnet Materials

65777 The poor fracture toughness of sintered Nd-Fe-B magnets makes it very difficult to produce magnetic parts with complicated shapes, tiny thicknesses, and small dimensions. Chipping, cracking, and fracture often happen during grinding, assembly, and operation of the Nd-Fe-B magnetic parts. Bonded Nd-Fe-B magnets could overcome these problems, but their magnetic performance is only one-eighth to one-tenth that of anisotropic sintered magnets. This project will utilize a plasma spray process to synthesize high performance and high fracture toughness Nd-Fe-B magnets with near net shape, thin thickness, small dimension, and complicated geometry. It also would be a better process for fabricating new bulk anisotropic nanocrystalline and nanocomposite Nd-Fe-B magnets. Phase I demonstrated the feasibility of using a plasma spray to synthesize Nd-Fe-B magnets. Very high coercivity was readily obtained in the as-deposited condition or after anneal, and strong magnetic anisotropy was observed. Ring magnets with soft iron used for magnetic flux return path were successfully fabricated. The production of amorphous Nd-Fe-B alloys was easier with plasma spray than other processes, such as melt spinning or mechanical alloying. Phase II will further improve the microstructure and magnetic performance of plasma sprayed Nd-Fe-B magnets by optimizing compositions as well as plasma spray and annealing conditions. High-performance anisotropic Nd-Fe-B magnets will be fabricated by creating a crystal texture during plasma spay. Bulk anisotropic nanocrystalline and nanocomposite Nd-Fe-B magnets with a breakthrough maximum energy product also will be synthesized. Commercial Applications and Other Benefits as described by the awardee: The plasma spray synthesis process should significantly reduce production cost and shaping efforts; stimulate new design ideas and new applications; improve device performance; and reduce device weight, volume, and energy consumption. Applications include generators, actuators, speakers, printers, and motors, including those widely used in computer hard and floppy disk drives, Zip, CD, and DVD disk drives