Effect of La–Y co-substitution on magnetic properties and microstructure of NdFeB alloy ribbons

Abstract

Committed to obtaining cost-effective NdFeB based permanent magnets, Nd27–xLa3YxFebalAl0.1Cu0.1B1 (x = 0–3) alloys were fabricated to detect the magnetic properties and microstructure. When x = 1.8, coercivity of 1004 kA/m and the magnetic remanence of 0.75 T are obtained, which are close to those of the original Nd30FebalAl0.1Cu0.1B1 alloy ribbons. The temperature coefficient of coercivity (β) and the temperature coefficient of remanence (α) of the LaY-substituted alloys are better than those of the original alloys. The research results manifest that La is mainly distributed in the grain boundary phases and plays the role of refining the main grains, optimizing the grain boundary phases and improving the wettability between the main phases and the grain boundary phases, while Y tends to enrich in the main phases and enhances the short-range exchange coupling.