Abstract: Disclosed are an R—Fe—B-based sintered magnet with a low B content and a preparation method therefor. The sintered magnet comprises the following components: 28.5 wt %-31.5 wt % of R, 0.86 wt %-0.94 wt % of B, 0.2 wt %-1 wt % of Co, 0.2 wt %-0.45 wt % of Cu, 0.3 wt %-0.5 wt % of Ga, 0.02 wt %-0.2 wt % of Ti, and 61 wt %-69.5 wt % of Fe. The sintered magnet has an R6-T13??M1+? series phase accounting for 75% or more of the total volume of grain boundaries. The present invention selects optimal content ranges of R, B, Co, Cu, Ga, and Ti, and forms an R6-T13??M1+? series phase of a special composition and increases its volume fraction in grain boundary phases, so as to acquire higher Hcj and SQ values.

Abstract: An R-T-B magnet includes the following components of: ?30.0 wt % of R, the R is a rare earth element; 0.02-0.14 wt % of Nb; 0.2-0.48 wt % of Cu; ?0.24 wt % of Ti+Nb; ?0.50 wt % of Al+Cu; ?0.955 wt % of B; and 58-69 wt % of Fe, wherein wt % is the mass percentage of respective component in the total mass of all components. The R-T-B magnet has remanence, coercivity, high-temperature stability and squareness at a better level. A method prepares the R-T-B magnet.