Improvement of the magnetic properties of low-neodymium magnets by minor addition of titanium

Abstract Rapidly solidified nanocomposite Nd 9 Fe 77− x B 14 Ti x alloys, consisting of magnetic Nd 2 Fe 14 B phase and soft magnetic phases, were investigated. The effect of titanium addition on the structure and magnetic properties was studied. It was found that 2–4 at% Ti addition leads to substantial increase of the coercivity and maximum energy product, maintaining the remanence unchanged. The highest properties: J r =0.81 T, J H c =907 kA/m, (BH) max =99 kJ/m 3 , were achieved for the Nd 9 Fe 73 B 14 Ti 4 alloy. This effect we attribute to the formation of fine and homogeneous grain structure and a change of the phase morphology in the Ti-containing alloys. The initial magnetization curve indicates a change of the coercivity mechanisms giving rise to pinning of domain walls, which is caused by reduction of the crystallite size.