MAGNETIC ALLOYS OF IRON, NICKEL, AND COBALT 449 



back of the diagram — and the low values for some of the cobalt-iron 

 alloys in the 45-70 per cent cobalt range of compositions. 



In the discussion of the magnetic properties of these alloys, I have 

 pointed out that there are three regions of composition which are of 

 special interest from the standpoint of applications because of their 

 unusual magnetic properties. One of these is in the iron-cobalt series. 

 A representative alloy of this group is the 50 per cent cobalt com- 

 position. In Fig. 10 the magnetization curves for this alloy and for 



/J- 



Fig. 10 — Magnetization and permeability curves for the 50 per cent iron, 50 per 

 cent cobalt composition and for Armco iron. 



a sample of iron are shown on the left and the permeability curves 

 plotted against the same scale of intrinsic inductions on the right. 

 The scale for the magnetizing force of the magnetization curve is 

 at the top of the figure. Below an induction of 1,000 and above 

 13,000 the permeability of the alloy is higher than for iron. Its 

 initial permeability is 600 and the maximum permeability is 4,000. 

 For a magnetizing force of 100 gauss the intrinsic induction is nearly 

 23,000 gauss. For Armco iron the initial and maximum permeabilities 

 are 250 and 7,000, respectively, and the intrinsic induction for a 

 magnetizing force of 100 gauss is 17,000. 



