Comparison on the magnetic properties and microstructure of directly casted Nd-Fe-Ti-B and Nd-Fe-Ti-Zr-Cr-B-C rod magnets with various diameters

Magnetic properties and microstructure of directly quenched Nd9.5Fe72.5Ti3B15 and Nd9.5Fe71.5Ti2.5Zr0.5Cr1B14.5C0.5 rod magnets with various diameters of 0.7-1.5 mm have been investigated. TMA shows that all the studied alloy rods mainly consist of a large amount of a 2:14:1 phase. Although the magnetic properties of these two alloys are decreased with the increase of diameter, the latter alloy, consisting of more elements, can preserve attractive magnetic properties up to a larger diameter of 1.3 mm, due to the grain refinement effect induced by multi-component substitutions.