Microstructures and the magnetic properties of Fe3B/(Nd, Dy)(2)Fe14B nanocomposite microalloyed with Cu and Zr

The effect of Zr and Cu addition to a Nd3.4Dy1Fe72.3B18.5Cr2.4Co2.4 alloy o n the microstructure and the magnetic properties of Fe3B/Nd2Fe14B nanocompo site has been investigated by a three-dimensional atom probe (3DAP) and tra nsmission electron microscopy (TEM). Addition of a small amount of Zr and/o r Cu is effective in improving the hard magnetic properties of the base all oy. Cu atoms form clusters in the early stage of crystallization, and Zr at oms are segregated at the interfaces of Fe3B/Nd2Fe14B being rejected from t he Fe3B soft magnetic phase on the optimal heat-treated condition. This cau ses refining the nanocomposite microstructure, resulting in improved hard m agnetic properties compared to those of the base alloy.