This　study　investigates　the　effects　of　zirconium　addition　on　the　structural　and　magnetic　properties　of　Nd-Fe-B　magnets,　with　a　particular　focus　on　the　grain　boundary　diffusion　(GBD)　process.　Zr　addition　promotes　grain　refinement　and　increases　the　amount　of　the　RE6(Fe,　M)14　phase.　The　increase　in　the　RE6(Fe,　M)14　phase　reduces　the　ferromagnetic　coupling　between　adjacent　RE2Fe14B　grains,　leading　to　a　4.21　kOe　improvement　in　coercivity　for　the　original　magnets.　Moreover,　the　RE6(Fe,　M)14　phase　shows　a　lower　affinity　for　the　Dy　element　compared　to　RE2Fe14B　phase,　thereby　promoting　the　incorporation　of　Dy　into　the　grains　of　the　latter.　These　effects　enhance　the　diffusion　depth　of　Dy　at　the　grain　boundaries　(GBs)　and　optimize　the　core-shell　structure　of　the　main　phase　grains.　Consequently,　a　coercivity　of　23.24　kOe　and　a　maximum　energy　product　of　46.69　MGOe　are　achieved,　with　a　notably　minimal　Dy　consumption　when　compared　to　magnets　of　similar　performance　produced　by　other　methods.　It　thus　provides　valuable　insights　into　the　relationships　between　alloying　elements,　grain　boundary　phases,　and　the　diffusion　process,　offering　guidance　for　the　design　of　high-performance　GBD　magnets.　©　2025