MENUSHENKOV V.P. National Research Technological University “MISiS”

Spoluautoři A.G. SAVCHENKO, Kateřina SKOTNICOVÁ, Miroslav KURSA

Sintered Nd-Fe-B permanent magnets with an enhanced coercive force were fabricated (i) using the main Nd14,5Dy1,5Fe75Co2B7 alloy and its mixtures with [Dy/Al], Tb2O3, Nd3Co additions and (ii) by postsintering heat treatment of magnets. The average grain size of the Nd2Fe14B phase decreases with increasing contents of [Dy/Al], Tb2O3 and Nd3Co additions and their liquidus temperatures. The mixing method is effective for all type of additions. The maximum coercive force magnitudes were reached after aging at 550oC, which was performed after cooling from sintering temperature to room temperature. The same aging performed after cooling from sintering temperature to 550 °C, i.e., without the intermediate cooling does not increase Hci. The correlation between structural changes and hysteresis properties of the heat-treated magnets has been discussed.