Bismanol

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Bismanol is an magnetic alloy of Bismuth and Manganese (Manganese Bismuthide) developed by the US Naval Ordnance Laboratory.

History[edit]

Bismanol, a permanent magnet made from powder metallurgy of Manganese Bismuthide, was developed by the US Naval Ordnance Laboratory in the early 1950s - at the time of invention it was one of the highest coercive force permanent magnets available, at 3000 oersteds.[1] Coercive force reached 3650 oersteds and flux density 4800 by the mid 1950s. The material was generally strong, and stable to shock and vibration, but had a tendency to chip. Slow corrosion of the material occurred under normal conditions.[2]

The material was used to make permanent magnets for use in small electric motors.[3]

Bismanol magnets have been replaced by Neodymium magnets which are both cheaper and superior in other ways, Samarium-Cobalt magnets in more critical applications, and Alnico magnets.[citation needed]

References[edit]

  1. ^ "Bismanol", Physics Today: 19, August 1952, doi:10.1063/1.3067699 
  2. ^ Adams, E.; Hubbard, W.M. (1953), "BISMANOL PERMANENT MAGNETS, EVALUATION AND PROCESSING", Naval Ordnance Lab., USA 
  3. ^ Adams, Edmond (1953). "A New Permanent Magnet from Powdered Manganese Bismuthide". Rev. Mod. Phys. 25 (1): 306–307. doi:10.1103/RevModPhys.25.306.