Rare earth magnet alloy ingot, manufacturing method for the same, r-t-b type magnet alloy ingot, r-tb type magnet, r-t-b type bonded magnet, r-t-b type exchange spring magnet alloy ingot, r-t-b type exchange spring magnet, and r-t-b type exchange spring bonded magnet

An R-T-B type exchange spring magnet alloy ingot, wherein the R-T-B type exchange spring magnet alloy ingot is produced by receiving a molten alloy of rare earth metal alloy by means of a rotary body;

• sprinkling the molten alloy by the effect of rotation of the rotary body, and causing the sprinkled molten alloy to be deposited and solidify on an inner wall surface of a rotating cylindrical mold;
• wherein a film having a thermal conductivity lower than that of material comprising the mold is provided to the inner wall surface of the cylindrical mold;
• wherein the R-T-B type exchange spring magnet alloy ingot comprises at least one element selected from Nd, Pr, and Dy in a total amount of 1 to 12% by atom and B in an amount of 3 to 30% by atom, with a balance being T (T represents a substance predominantly comprising Fe, with a portion of Fe atoms being optionally substituted by Co, Ni, Cu, Al, Ga, Cr, and Mn);
• the R-T-B type exchange spring magnet alloy ingot is produced through formation of a composite of crystal grains of a hard magnetic phase and crystal grains of a soft magnetic phase;
• and
• the R-T-B type exchange spring magnet alloy ingot contains crystal grains of a hard magnetic phase having a grain size of 1 μm or less and crystal grains of a soft magnetic phase having a grain size of 1 μm or less in a volume of at least 50% on the basis of the entire volume of the alloy.