DocumentCode :
1042526
Title :
Investigations of high-coercivity alnico alloys
Author :
Hoffmann, Alfred ; StÄblein, Heijmut
Author_Institution :
Fried. Krupp GmbH Zentralinstitut für Forschung und Entwicklung, Essen, Germany
Volume :
6
Issue :
2
fYear :
1970
fDate :
6/1/1970 12:00:00 AM
Firstpage :
225
Lastpage :
230
Abstract :
For Alnico alloys containing 32-42 percent Co, 0-9 percent Ti, 6-8 percent Al, 14 percent Ni, 3 percent Cu, 0-0.5 percent S, 0-2 percent Nb, remainder Fe, the liquidus and solidus temperatures and the upper limit of the (α + γ) phase field were determined. The greatest influence is exerted by titanium in that all temperatures decrease as the Ti content increases. The influence of cobalt on temperature is considerably smaller, while sulfur has no influence at all. The addition of 2 percent Nb resulted only in the upper limit of the (α + γ) phase field being shifted to temperatures 20 to 30°C lower. Alnico alloys containing about 39 percent Co and 7-8 percent Ti were brought to columnar crystallization by controlled cooling, using a seed crystal. The seed contained 6 percent Ti and the lowering speed was between 0.50 and 3.75 cm/h. At a lowering speed of 0.50 cm/h and a temperature gradient of 5 to 10°C/mm, it was possible to obtain columnar crystallization without using a seed. The following magnetic values were obtained: (BH)_{\\max } = 11.0-11.7 MG.Oe,B H_{c} = 1780-2100 Oe, B_{r} = 8920-10 050 gauss.
Keywords :
Alnico alloys; Aluminum alloys; Cobalt alloys; Cooling; Copper alloys; Crystallization; Iron alloys; Nickel alloys; Niobium alloys; Temperature control; Titanium alloys;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.1970.1066731
Filename :
1066731
Link To Document :
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