Coballoy : a new permanent-magnet alloy


Forster, Bryan Douglas




Northern Electric Co. Ltd. Research and Development Laboratories is currently developing the SP-1 Electronic Switching System. This switching system is under the control of a program stored in a semi-permanent memory which uses as its bit element the Piggyback Twistor.

Successful performance of the semi-permanent memory, and hence the swîtching system, is dependent upon successful performance of the Piggyback Twistor. Achievement of this is heavily dependent upon obtaining the correct magnetic characteristics in two tapes of dissimilar magnetic materials, one of high coercive force and the other of low coercive force, used in the construction of the Piggyback Twistor.

A new alloy of cobalt, iron, and goid, called Coballoy, has recently been disclosed by the Bell Telephone Laboratories Inc. and proposed for the high coercive force magnetic material in the Piggyback Twistor.

It is with the metallurgy of this alloy and with the development of a metallurgical process which brings out the desired magnetic characteristics in this alloy for its use in the Piggyback Twistor that this thesis is primarily concerned. Magnetic, crystallographic, and metallographic data on the alloy are presented. The relationship between coercive force and metallurgical processing is discussed. Finally, hysteresis loop squareness is related to the development of a preferred orientation in the tape through crystalline, anisotropy energy.


Cobalt Alloys




Carleton University

Thesis Degree Name: 

Master of Engineering: 

Thesis Degree Level: 


Thesis Degree Discipline: 

Engineering, Materials

Parent Collection: 

Theses and Dissertations

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