The Arnold Engineering Company

Ralph M Handren

John P McKay

The invention relates to a novel alloy consisting essentially of 13-18% nickel, 7-11% aluminum, 0.5 to 10% cobalt, 0.1 to 2% silicon and the remainder substantially all iron, as is produced by heating the alloy composition to a temperature of about 1650.degree. C. or above to form a melt and then casting the melt in a suitable mold. After solidification, the casting is heated to approximately 1150.degree. C., held at that temperature for a sufficient time to insure that the whole mass is heated uniformly, and then cooled at the rate of about 300.degree. C. per minute. Parts are then given an aging for the purpose of producing uniform magnetic properties throughout the casting. Magnets thus cast, heat-treated and aged as aforesaid produce very stable magnetic properties with typical values of Br = 10,000, Hc = 150 and BH max = .85. A further improvement in properties can be achieved by a second stage heat treatment wherein castings are heated to about 900.degree. C., held at this temperature for a sufficient time to assure that the whole mass is heated uniformly, and then cooled to about 600.degree. C. at the rate of 60.degree. C. per minute, followed by aging. Parts thus treated with the second stage heat treatment produce very stable magnetic properties with typical values of Br = 9,500, Hc = 230 and BH max = 1.2. These properties are extremely well suited to many hysteresis torque producing devices.

Hysteresis alloy

The invention relates to a novel alloy consisting essentially of 13-18% nickel, 7-11% aluminum, 0.5 to 10% cobalt, 0.1 to 2% silicon and the remainder substantially all iron, as is produced by heating the alloy composition to a temperature of about 1650.degree. C or above to form a melt and then casting the melt in a suitable mold. After solidification, the casting is heated to approximately 1150.degree. C, held at that temperature for a sufficient time to insure that the whole mass is heated uniformly, and then cooled at the rate of about 300.degree. C per minute. Parts are then given an aging for the purpose of producing uniform magnetic properties throughout the casting. Magnets thus cast, heat-treated and aged as aforesaid produce very stable magnetic properties with typical values of Br = 10,000, Hc = 150 and BH max = .85. A further improvement in properties can be achieved by a second stage heat treatment wherein castings are heated to about 900.degree. C, held at this temperature for a sufficient time to assure that the whole mass is heated uniformly, and then cooled to about 600.degree. C at the rate of 60.degree. C per minute, followed by aging. Parts thus treated with the second stage heat treatment produce very stable magnetic properties with typical values of Br = 9,500, Hc = 230 and BH max = 1.2. These properties are extremely well suited to many hysteresis torque producing devices.

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Crystal Lake, IL, United States of America

Ralph M Handren