Alloy lump for r-t-b type sintered magnet, producing method thereof, and magnet

摘要

The present invention is an alloy lump for R-T-B type sintered magnets, including an R₂T₁₄B columnar crystal and an R-rich phase (in which R is at least one rare earth element including Y, T is Fe or Fe with at least one transition metal element except for Fe, and B is boron or boron with carbon), in which in the as-cast state, R-rich phases nearly in the line-like or rod-like shape (the width direction of the line or rod is a short axis direction) are dispersed in the cross section, and the area percentage of the region where R₂T₁₄B columnar crystal grains have a length of 500 mum or more in the long axis direction and a length of 50 mum or more in the short axis direction is 10% or more of the entire alloy.