TRANSACTIONS OF SECTION G. 685 
5. The Production of Magnetic Alloys from Non-magnetic Metals. 
By R. A. HApFIELD. 
Having some years ago produced a non-magnetic iron alloy known as ‘manganese 
steel,’ I was much interested in learning that with the same metal, manganese, 
which had enabled me to obtain a practically non-magnetic iron alloy, it had been 
found possible to produce a magnetic copper alloy. 
I have had communications with Dr. F. Heusler, who has given me much 
interesting information, I have myself also produced some of this alloy, as exhi- 
bited to-day. 
It is of course well known that the metals copper, aluminium, and manganese, 
are non-magnetic. It is, therefore, to say the least, surprising to find that, com- 
bined in certain proportions, they produce an alloy having quite considerable 
magnetic properties, 
It may be first mentioned that no combination of copper with aluminium 
produces a magnetic alloy; the peculiar change noticed, therefore, must be ascribed 
entirely to the presence of manganese metal—the same metal which in manganese 
steel produces the profound change in iron, converting it from its well-known 
magnetic to non-magnetic condition. 
‘As it was thought that perhaps the manganese metal under certain conditions 
might show some reversibility, as is the case with certain iron-nickel alloys which, 
whilst being non-magnetic at ordinary temperatures, become magnetic at low 
temperatures—6U to 80°C.—_Sir James Dewar himself submitted the manganese 
metal I used in producing the alloy exhibited to the temperature of liquid air. 
No change was found to occur; the metal remained as non-magnetic as at ordinary 
temperatures. This, of course under the same test, was found to be the case with 
the copper and aluminium used in my experiments. 
The alloy exhibited contains 60 per. cent. copper, 25 to 27 per cent. man- 
ganese, and 12 percent. of aluminium. The manganese metal used contained about 
92 per cent. manganese, the rest being 6 to 7 per cent of silicon, ‘5 to 1 per cent. 
of carbon, and probably 0:50 per cent. of iron. But Dr. Heusler has shown that 
with absolutely no iron present the magnetic qualities are exactly the same. 
Another very curious point is, that whilst it must be the manganese which 
confers the magnetic properties, the ‘reversibility,’ so to speak, is brought about 
by the aluminium. 
For example, with the manganese fairly constant 25 to 28 per cent., and the 
aluminium varying from 3 to 14 per cent., the magnetisability with 3 per cent. is 
nil; 5 per cent. confers a little; 10 per cent. is still more; the maximum being 
reached with 14 per cent, aluminium :— 
|] 
Specimen Numbers. Analysis per cent. | iam Mo yee & Hawse) ; 
N60 Maafol AB F 0. 
34 28 36 ze Unmagnetisable. 
35 28 57 | 3 Very slightly magnetisable. 
36 26 9-6 3 2,220, 2,670, 3,200, 3,470. 
32 26 14-6 & 4,500, 4,850, 5,380, 5,550. 
33 | 25 13'8 fi 3,580, 4,075, 4,645, 4,900. 
| 
Dr. Heusler states that the magnetisability of the alloy will increase with an 
increased percentage of aluminium, the maximum for any stated percentage of the 
manganese being attained when the aluminium percentage amounts to, roughly, one- 
