R-T-B-based rare earth magnet particles, process for producing the R-T-B-based rare earth magnet particles, and bonded magnet

A process for producing R-T-B-based rare earth magnet particles, comprising steps of:

• subjecting a raw material alloy comprising:
• R, wherein R represents at least one rare earth element including Y,
• T, wherein T represents Fe, or Fe and Co,
• B, wherein B represents boron, and
• Al, wherein Al represents aluminum,
• to HDDR treatment to obtain Al-containing R-T-B-based rare earth magnet particles having an Al content of more than 0 atom % and not more than 1.0 atom %;
• and
• heat-treating the Al-containing R-T-B-based rare earth magnet particles in vacuum or in an Ar atmosphere at a temperature of not lower than 670° C. and not higher than 820° C. for a period of not less than 30 min and not more than 300 min,
• wherein the R-T-B-based rare earth magnet particles do not comprise Nb,
• wherein the R-T-B-based rare earth magnet particles have a coercive force of not less than 1290 kA/m, and
• wherein the R-T-B-based rare earth magnet particles have a residual magnetic flux density of not less than 1.25 T.