On the correlation "powder dispersivity - hysteresis characteristics" for (Sm,Zr)(Co,Cu,Fe)<sub>z</sub>-based magnets
Correlations between the morphology and magnetic properties of (Sm,Zr)(Co,Cu,Fe) z alloy powders and magnetic characteristics of magnets prepared from the powders are shown. The dependences of the main parameters of sintered magnets on the basis of alloys (Sm, Zr) (Co, Cu, Fe)z on the time of powder milling are considered taking into account the morphology, average particle size and magnetic properties of the powder itself. It was found the existence of monotonic variations of the average powder-particle size and density of prepared permanent magnets with changing milling time of alloy in a planetary ball mill. The dependences of main magnetic characteristics of magnets on the milling time exhibit the extreme corresponding to the optimum milling time of powder (the milling time for obtaining maximum values is 7 min). The corresponding dependencies of the powder particle size and the density of the sintered samples are monotonic The correlation between the average powder particle size, particle morphology, magnetic properties of powders and permanent magnets prepared from the powders is analyzed taking into account the efect of subsequent sintering of powder blanks. It is assumed that the coincidence of the powder milling times necessary for obtaining the maximum magnetic parameters of freely oriented powders and sintered magnets ( t = 7 min) is occasional.