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Magnetic Properties of Alloys Containing Mischmetal, Cobalt, Copper, Iron, and Magnesium.

Walkiewicz JW; Winston JS; Wong MM
MISSING :22 pages
The Bureau of Mines investigated alloys containing mischmetal (mm), cobalt, copper, magnesium, and iron for use in permanent magnets in place of the scarce samarium-cobalt alloys. The magnetic properties of mm-co, mm-co-cu, mm-co-cu-mg, and mm-co-cu-fe-mg alloys were evaluated. Magnets were fabricated by powder metallurgy consisting of arc-melting the metals, crushing and grinding the resultant alloys, alining and compacting the powder, and sintering the compacts. Magnetic values of mhc = 4.7 Koe, bhc = 4.07 Koe, br = 6.81 Kg, and (bh)max = 10.0 Mgoe were obtained with a mm-co alloy containing 36 +/- 0.05 wt-pct mm. By substituting copper and magnesium for part of the cobalt, the values for mhc and bhc were increased to 29.0 Koe and 5.89 Koe, respectively. This intrinsic coercivity value exceeded that of sm-co alloy obtained in our laboratory. The addition of iron to mm-co-cu-mg alloys resulted in an increase of br to 6.90 Kg and (bh)max to 10.3 Mgoe. Copper and magnesium contents of these alloys were optimized to obtain maximum values of hc.
Publication Date
Document Type
IH; Report of Investigation;
Fiscal Year
Identifying No.
RI 8583
NIOSH Division
Source Name
Page last reviewed: November 19, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division