A nanocomposite structure in directly cast NdFeB based alloy with low Nd content for potential anisotropic permanent magnets

摘要

The magnetic properties of NdFeB magnets can be tailored with different kinds of microstructures. In this work, a nanocomposite structure with amorphous phase remaining inside the micro-sized Nd2Fe14B type grains was observed by Scanning and Transmission Electron Microscopy on the suction cast Nd11Fe60Co10Ti2.5Nb0.5C0.5B15.5 alloy, and then confirmed by various characterization techniques. The worm-like soft magnetic amorphous phases show strong exchange coupling with Nd2Fe14B phase. As a result, the open recoil loops, which are typical characteristics for nanocomposite alloys consisting of hard and soft magnetic phases, have been clearly evidenced. Thus, the formation of this structure may provide an alternative approach to design and fabricate anisotropic nanocomposite NdFeB-based permanent magnets with enhanced magnetic properties. (C) 2017 Elsevier Ltd. All rights reserved.