US Government as Represented by the Secretary of the Army

Robert L Bergner

Arthur Tauber

Frederick Rothwarf

Herbert A Leupold

The reversible temperature coefficient of magnetization of a permanent magnet alloy over the temperature range from -50 degrees C. to +150 degrees C. is lowered by heat treating the alloy in a noble gas atmosphere or in a vacuum by the steps of (a) heating the alloy at about 1150 degrees C. for 1.5 hours (b) quenching the alloy in ice water, (c) heating the alloy at about 940 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for 2 hours, and (g) lowering the temperature to about 400 degrees C. and heating for 10 hours.

Method of treating Sm.sub.2 Co.sub.17 -based permanent magnet alloys

Magnetic alloys of the general formula Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12-x M.sub.x are provided wherein M is Mn or Cr and wherein x is a value greater than zero and less than 2.1.

Magnetic alloys

Compounds of the general formula Sm.sub.2-x RE.sub.x Co.sub.17-y Mn.sub.y are provided wherein RE is a rare earth element selected from the group consisting of erbium, dysprosium and gadolinium wherein x has a value greater than zero and less than 0.7 and wherein y has a value less than 2.1. The compounds are suitable for use as permanent magnet material in microwave/millimeter-wave traveling wave tubes (TWT's).

Permanent magnet materials

The reversible temperature coefficient of magnetization of a permanent magnet alloy is lowered by (a) heating the alloy at about 1200 degrees C. for 2 hours, (b) quenching the alloy in ice water, (c) heating the alloy at about 850 degrees C. for 2 hours, (d) lowering the temperature to about 700 degrees C. and heating for one hour, (e) lowering the temperature to about 600 degrees C. and heating for one hour, (f) lowering the temperature to about 500 degrees C. and heating for one hour, (g) lowering the temperature to about 400 degrees C. and heating for four hours, and (h) lowering the temperature to about 280 degrees C. and heating for 12 hours. The method is particularly effective in lowering the reversible temperature coefficient of magnetization of the permanent magnet alloy Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12.

Growing community of inventors

Randolph, NJ, United States of America

Robert L Bergner