W-containing R—Fe—B—Cu sintered magnet and quenching alloy

A W-containing R—Fe—B—Cu serial sintered magnet, comprising:

• an R2Fe14B-type main phase, the R being at least one rare earth element comprising Nd or Pr,
• wherein a crystal grain boundary of the W-containing R—Fe—B—Cu serial sintered magnet comprises a W-rich area with W content above 0.004 at % and below 0.26 at %, the W-rich area distributed with a uniform dispersion in the crystal grain boundary, and accounting for 5.0 vol % to 11.0 vol % of the W-containing R—Fe—B—Cu serial sintered magnet,
• wherein in the raw material of the W-containing R—Fe—B—Cu serial sintered magnet, R content is 12 at % to 15.2 at %, B content is 5 at % to 8 at %, W content is 0.0005 at % to 0.03 at %, Cu content is 0.05 at % to 1.2 at %, X content is below 5.0 at %, the X being selected from at least one element of Al, Si, Ga, Sn, Ge, Ag, Au, Bi, Mn, Nb, Zr or Cr, the total content of Nb and Zr is below 0.20 at % when the X comprises at least one of Nb or Zr, Co content is 0 at % to 20 at %, and the balance is Fe and inevitable impurities, and
• wherein O content of the W-containing R—Fe—B—Cu serial sintered magnet is 0.1 at % to 1.0 at %.