Control of the Properties of Sm – Fe – Co – Cu – Zr Magnets by the Method of Mixtures of Powders

The effect of the chemical composition of the alloys on the magnetic properties of sintered Sm – Co – Fe – Cu – Zr magnets produced with mixing of alloy powders is studied. Elevation of (BH )max of Sm – Co – Fe – Cu – Zr magnets due to increase of the concentration of Fe to 20 wt.% requires observation of a strict proportion of the components and precision choice of the modes of heat treatment. Optimization of the chemical composition and use of step annealing with reduction of the temperature from 700 to 400°C has given sintered magnets with the following properties: Br = 11.7 – 11.9 kGs, HcB = 9 – 10 kOe, HcJ = 15 – 20 kOe, and (BH )max = 29 – 31 MGs · Oe.